The humans created the Cylons
No. The whole 'machines turning on their creators' thing has been done so many times that having the Cylons be a Colonial creation would add nothing.
Now having the origin of the Cylons and the reason for their hostility towards Humanity a mystery that's gradually solved, THAT has potential.
Cylons have been working on making human form Cylons
One of the few good ideas Galactica 1980 had, since it increases the threat of the Cylons (i.e. the ever-present danger of infiltrators/saboteurs).
The Battlestar Galactica is a old rust bucket due to be retired and converted into a museum before the Cylon attack
Not sure about the museum thing, unless that's somehow important to the story, but the Galactica being old and in less-than-mint condition would definitely add to the show.
The show would have more drama
In this day and age, that's pretty much a given.
Lasers, and energy weaponry would have been replaced by missiles and projectile weaponry.
Not entirely sure about this one. On the one hand, it would help differentiate the show from other Sci-Fi shows, but on the other hand, you don't want to change too much about the show (otherwise, what's the point of calling it 'Battlestar Galactica' when you could just do a completely original show) and I don't really see how removing the energy weapons would make the show inherently better.
Personally, I would keep the energy weapons in some form or another, but tone them down from the Star Wars-esque 'lasers' of the original into something more grounded in reality, like Babylon 5's Plasma-based weaponry. The missiles would be a good addition too.
Other than the stuff I've mentioned above, one of the first things I'd do is remove Muffitt (i.e. that stupid robot dog). Boxey, I might keep since there is potential in that character if used appropriately.
The next thing would be to give Lord Baltar an actual reason for betraying the Colonies (tricked into it perhaps?) rather than just having him join the Cylons because the script says so. Here's a thought - what if Lord Baltar (after inadvertently playing a role in the Cylon victory) is left as the highest ranking political leader? Imagine him trying to lead the survivors while trying to conceal his role in the Fall of the Colonies AND butting heads with the military commander, Adama.
Athena would be a pilot and an actual character rather than the somewhat 2-dimensional Bridge-bunny she was in the original. Making her a pilot would also help address the fact that all the main character pilots from the original (Starbuck, Apollo & Boomer) are male (because you just know someone will point that out and make a fuss) without having to resort to arbitrary gender-swaps.
The Battlestar Pegasus, or some equivalent, would play a larger role (as it was supposed to in the original - there were plans for it to return in later episodes).
That's all I've got at the moment.