Yes to falling asleep then waking up and wanting to feed - totally normal. It does ease off as they get more alert and stay awake for longer periods at a time.
If you want to protect BF then it's best to keep FF to one set time and not give any other FFs except this feed. If you feel you don't have enough milk, breastfeed more rather than going to formula. The more you feed the more you make. But certainly you can work around one FF per day :) I think that giving it as a full feed is much better than topping up, and I'd stick to this. You'll adjust to the routine as long as you stick to it. However, supply is not actually so rigid that you will produce exactly enough for all minus one formula feed. But it helps to have the FF at a predictable time, and not to fall back on FF every time when you feel worried about supply or when you feel that the baby needs a bit extra or when you don't feel like it, especially if it's likely that you'll creep more and more into using FF, and especially if you're doing it for supply worries or baby fullness worries. (Because the way to make more milk is to feed more, so by doing the opposite, it perpetuates the problem.) Of course it's fine to give a FF if you are feeling overwhelmed or you want to go out or whatever, but bear in mind that introducing too many FFs too quickly can impact on supply, which is more fragile before you enter the demand-based phase which happens at 3-4 months.
Hard to give a time scale on when it gets easier, because it's different for every mother-baby pair, but most women find a shift or change after one of these points:
6-8 weeks - past initial "boot camp" and the first growth spurt.
3-4 months - shift from hormonal to demand based supply. You won't feel as uncomfortable between feeds, you may stop leaking. End of "newborn" phase, baby starts to be more alert and interested in the world.
6 months - baby has passed 4 month sleep regression, can now eat solids so BF no longer the only form of nutrition.
However for others it's more of a gradual shift and you can't pin down a specific point where it got better, but over time you just both got better at things.
Might be worth looking at the app called Wonder Weeks, I know friends with babies who absolutely swear by it. It's a nice one to know what's coming up, very reassuring if you like that kind of thing.