For future things for Russia, sooner or later, a nationalist regime will take over in Poland, then there can be a repeat of the November Uprising, just worse as ATL Poland is rather bigger than Congress Poland.
The Congress Poland was under the Russian control and the main issue for the uprising was, AFAIK, what the Poles considered infringement upon their constitutional rights. IITL Poland is a completely independent state so this hardly can be an issue. From the PR point of view in the last war Russia acted as a protector of the Polish <whatever> and Poland even got some of the lands back and gained some military glory. Of course, sooner or later the hot heads may decide that it is a good idea to return all lands lost to Prussia and Austria and this may end up badly but we are not at that point, yet.
Could have another partition afterward depending what the geopolitical context is then (OTL third partition territories probably wouldn't have been too much of a problem if Alexander hadn't decided to make the Polish heartland also part of the empire).
ITTL the policy is to leave a big enough Polish buffer state and not allow the further partitions. Prussia and Austria got their shares but that’s it. No serious reason to encourage the further activities in that area.
European politics are also likely to be livelier then OTL 1815-1854, since it isn't as much of an end of history moment as the OTL Congress of Vienna. France is more able to throw its weight around, German nationalism will be a lot weaker, the HRE is still around, it will be more a continuation of pre-French Revolution dynamics. Not that that makes things easier for you, since you will not be able to rely on OTL history near as much going forward.
Well, so far I was pretty much avoiding the German affairs and will try to keep it that way… 😉
Russia also can act as the Gendarmerie of Europe whenever Central Europe has an ATL equivalent of 1848. Austria admittedly was not very grateful OTL, but as long as Russia is an absolute monarchy, they have a real interest in suppressing liberalism as it is somewhat contagious.
Making the Russian XIX politics as stupid as it was in OTL is not difficult but what’s the point? We already know what happened under this worst case scenario and the challenge, as I see it, is to avoid as many stupidities as possible while still remaining on the Planet Earth.
The British will probably have a scare about Russia at some point, they were prone to thinking whichever great power was doing well at any given moment was a terrifying threat. Then you could have an epic show-down of the British, Prussians, and Austrians versus Russia and perhaps France.
So far, Russia and Britain had minimal conflicts of interests and none of them was worthy of a serious confrontation. If Russia is not handicapped by the domestic backwardness (which is so far pretty much avoided), there would be very little “epic” in the Russian military confrontation with Prussia and/or Austria, especially if France is being involved. Anyway, what Britain is going to gain by such a confrontation?
Plus, there is nothing preventing Russia from stupid foreign policy.
See above. 😂
Looking at OTL great powers, ATL Russia having managed to maintain a broadly sane foreign policy for 100 years is quite impressive. Plenty of stupid, but plausible options: Caucuses (Can easily carve a bunch of land off Persia, just need to clear out the mountaineers to the north for access, easy as pie!), Ottoman Empire (Need to liberate our Slavic brothers, we're Third Rome, so need Constantinople, never mind that will upset all the other Great Powers), or heck, Sweden (Baltic provinces would be great! Who but an internationalist softy would worry about minor things like wrecking the Baltic trade, earning international infamy, or the pain of fighting a very well-run nation that will do a lot better than paper strengths suggest?).
You see, in OTL the Russian political course was heavily impacted by the foolish decisions made in the XVIII and then early XIX century. A not too bright ruler like NI or AII was pretty much a hostage of these decisions because deviation would result in what considered as a loss of a prestige. Now, if the initial stupidities are avoided or impact of their later implementation would be much smaller.
For example, getting into the Caucasus in the early XVIII, when all sides involved were on the same technological level, was a disaster, in the mid-/late-XVIII it started a prolonged bloody mess over pretty much nothing but in the 2nd half of the XIX it, including the mass expelling of the Circassians and conquest of Chechnya, happened relatively easily because the technological gap became a strategic factor.
Actually, as far as the Caucasus is involved, the only economically meaningful (even this in a retrospect) part of it did not require the acrobatic tricks needed for maintaining connections with Georgia. You are just moving Southalong the Caspian coast (starting from the Terek ITTL), taking Derbent. Then you are pretty much done and can go all the way to Baku or further. The “wild” tribes are on your right but their ability to project power beyond the cordon line is close to zero, their communications with the outside world are extremely limited and their spiritual leaders can’t even declare a jihad without being denounced by the Caliph.
“Carving” Persian Armenia and Georgia (multiple states and tribes)? Who
seriously needs them? There is nothing to loot there and, even when and if they are conquered, administration of “Georgia” is going to be a nightmare because every third “native” imagines himself an independent ruler. Historically, the whole charade started with a BS: to get Russian help in the fight against the Persians & Ottomans the local rulers (who were shifting between the Russians and traditional overlords almost on the daily basis) had been spreading the rumors about enormous mineral riches of their mountains (gold and pretty much everything else imaginable except for the very big diamonds). The first Romanovs (Michael or Alexey) started with sending the “researching party” which returned with a report after which the idea died. Peter was just itching for fighting somebody and launched his Persian expedition based, IIRC, upon speculations of Volynsky (who ended up as a martyr of the struggle against non-existing German tyranny, which does not change the fact that he was more than a little bit of a scumbag). The conquest proved a huge drain on the Russian finances and military force. Pretty much the same was the case with CII who was full of the “ideas” and rarely bothered herself with the details. After this Russian Empire pretty much stuck with a piece of Georgia which it could not abandon without a loss of face and to keep which it had to conquer the logistically worst pieces of the mountain area.
“Slavic brothers” actually came into the picture relatively late: AFAIK, neither Rumanians nor the Greeks are the Slavs. Of course, support of the panslavism by the Russian monarchs was rather touchy, taking into an account that by the time it came into existence the Romanovs were practically pure-breed Germans. There was a historic anecdote about AIII investigating his ancestry, especially the rumor that Paul was actually son of Saltykov. When such a possibility was confirmed he reacted “good, this means that I have at least some Russian blood”. Seriously, besides the hysteria in a rather narrow circle of the “educated classes” the practical part of the war of 1877-78 (if there was one, of which I’m anything but sure) was a revenge for the CW. And, BTW, with all idiocy involved, AII & Gorchakov spent few years (making the claim regarding help to the Serbs preposterous) achieving consent of the Great Powers for this adventure. So even the bottom level stupidity had some limits.
The Third Rome ideology was pretty much dead well before Peter I and actually it more or less involved a denial of Constantinople: the 1st & 2nd Rome fell for their sins so
“we (Muscovite state
) are the third Rome”. Actually, during the XIX century the Russian armies had been within a spitting distance from Constantinople but its annexation was not even considered: among other reasons it would be a fundamental logistical stupidity.
The Baltic Provinces had been reasonably “great” at the time of OTL PI but ITTL I don’t see how they are making too much sense by the early XIX. They are predominantly agricultural areas with the few port cities prospering mostly by transit trade the Russian part of which is done on the most favorable conditions and, anyway, Russia has its major port on the Baltic. The provinces still have their own traditional “liberties” and a high degree of a self-administration so their incorporation into the Russian legal and administrative structure is not going to be easy. On a positive side, due to almost complete absence of any perspectives in the area there is a consistent outflow of the most active segment of their nobility, merchants and artisans to Russia, which is very convenient: no obligations and a lot of benefits. Not to mention that these provinces are producing an useful buffer in the case of the future conflict with a (much stronger) Prussia. And, taking into an account that Sweden depends on the Russian support in the case of troubles in Germany, cordiality of that relation is based upon the mutual interests.
Caucasian adventure against Persia looks more plausible and, as in OTL, short of the (OTL) foolishness, it does not require a serious mess in the mountains. In OTL the problems with Chechnya had been quite separate from the Russian conquest of Azerbaijan.
Getting deeper into the CA mountains with the khanates and Dzungaria already Russian looks like an adventure just for the sake of adventure except for the research needed for figuring out a precise border with the British sphere of interests.
Now, as far as the prestige is involved, AIII was doing just fine explicitly avoiding any serious entanglement and the Russian international prestige was higher than during the reigns of AII and NII.