If you leave the driveway in front of where the garage door is, you may want to think about a curb stop or two so no cars accidentally accelerate into your new living room. You also mentioned leveling the graded garage floor so you are probably fine on this point, but, you will just want to make sure that outside the new wall water doesn’t run back and stand.
Yea I’ll definitely chop up the parking pad, don’t want cars directly in front of the window. I’ll probably leave a narrow portion as a walkway from the new garage to the front door.