It isn't necessarily good, your car is going to pull a little bit toward the new brake.
Did you try getting some kind of extension on the wrench? Like an aluminum tube or breaker bar to get leverage.
As long as you retighten any lugs on the tight lug wheel back up before driving and and pump up the brake pedal you will be fine. You need a half inch drive six sided socket on the lugs with a breaker bar to loosen. Or go to a friendly shop and they will loosen them with an impact AIR GUN for free.
Yes, As if left tyre brake pad is new you can change one set of brake pad.It doesnt effect on your brake system.
It is not good for the car at all. Your stopping distance and ability will be compromised. It sounds like your lug nuts are stripped. When that tire came off last, was it done at a shop? If so, take your car in there and explain to them that they put the nuts on wrong. If it wasn't done at a shop it is going to cost $ to get the nuts removed. If you are lucky only the nuts are stripped; the worst case is if both the nuts and posts are stripped.
Yes, since the new pads will overcompensate for the older ones. Did you ever think of using liquid wrench or PB Blaster on the lug nut that cannot come off?
Oh, and one more thing, did you turn/replace the rotors on the brakes you already replaced?
no
I've needed to change the brake pads on my car for a while now and some friends helped me last night. Somehow the lug nut on the other tire are too tight to get off, even with an impact drill... so my left tire has brand new brake pads but the right still have completely worn down ones. Is it bad to drive like that and how might I be able to get those lugs off???