You need to consider what they'll likely be able to do something about.
Squeaky floors are something they should be able to fix if they have open access from below (from the basement). If it's covered underneath, they would have to break a hole in the ceiling to fix it. If there is carpeting, they may be able to fix it from above; if it's laminate or hardwood flooring, they won't be able to without replacing the floor, which they will probably be unwilling to do.
Light switch panels they may or may not be able to make perfectly even. If there is enough wiggle room in the switches, they can probably move them. Otherwise, they will not be willing to tear out the electrical boxes just for that.
And that's what it really comes down to - how much they're willing and able to do, and how much you're willing and able to push it. If the local construction industry is really bad, they may be willing to do more to get you to sign quickly. On our house, they messed up an outside wall; though they repaired it, they were also willing to do extra landscaping to make up for it. If it's something they consider to be very small, they will be less willing to give in. In the scheme of things, I'd consider the light switches to be very small, but the floor squeaks are bigger.
One more thing: if they tell you "we'll see what we can do about X," rest confident that they will most likely not do anything about X. Even if they say they'll do it, they may not - depending on how busy they are. It's cheaper for them to have people chase them down later, because they can just stall you forever. And if they do, they may not do it the way you expect. We actually had a pipe sticking out of the wall in one place; they said they'd fix it, and they did, but instead of fixing the pipe, they did it by putting a false wall up over the pipe.
Finally, try to be reasonable. Most builders are decent people, just like us, and if you're reasonable with them, they'll be more reasonable with you. My mom used to work for a builder and I remember her telling me how some customers were completely unreasonable, demanding that floors be precisely level everywhere, etc. Unless you're talking a multi-million dollar custom built house, you can't expect perfection. From the way you phrase your question, I think you're fine on the reasonableness scale, and you'll probably do just fine.