Non-noble French officers of OTL simply ain't gonna be officers in this timeline,especially if the wars aren't as intense and prolonged as they were like OTL.A lot of them probably won't join the army to begin with.I suggest they either make cameo appearances or if they are actually lower soldiers,have them promoted to junior officer rank at most.As for Napoleon,it depends on who Napoleon makes friends with.There's a good amount of patronage going around in the Ancien Regime.
Not so sure about that, Murat was extremely unhappy about ending up in the church, Ney was an unenthusiastic notary, Masséna as I recall was frustrated by the fact he could advance no further and turned to smuggling. Lannes will maybe stay as a dyer, I'm not sure if Jourdan had another career outlined for him before he joined the army,. But one of the things I have noticed that many of them have in common is that many started their military careers as volunteers in a ROTC-type situation and it took off from there.
I know the Termidorian Reaction changed a lot of how the army functioned and everything, but is it possible for them to decide to chuck the old system (nobility as officers, etc) or not? I guess Bonaparte could become associated with the an alt-Jacobin movement, or maybe somehow impresses the Prince de Broglie (or one of the other more liberal military nobles guillotined)?
The usual consensus about alt-Napoléon is to block his promotion in the French army and send him on an adventure abroad instead (the Ottoman empire and the USA are very popular, I remember seeing India or South America quoted once or twice as well). He could have played a delayed Lafayette-like role, but now that the USA are freedomed he could maybe play an alt-Bolivar? (I don't think the Bolivar-San Martin generation could exist without the Bonaparte example).
Except my plan is to keep the Bonapartes in France, perhaps with Joseph ending up as a bishop (before he switched to law he was destined for the church IIRC), Napoléon as a successful soldier rags-to-riches (or a mathematics professor, since he envisioned that career for himself if he hadn't been a soldier), and maybe an alt-Jérôme ending up climbing the rungs in the navy. I don't doubt Napoléon could be sent to the Ottomans as he contemplated OTL to reform their artillery, perhaps he'll do that, and come back with glowing reports from Constantinople.