I have an impact drive and drill. I was thinking a cheap option to leave in the truck for when I want to quickly pull things off away from homeHow much are you trying to spend? Typically these kinds of bits are used with an impact driver but you have to be careful about how hard you go with it. I have a Milwaukee M12 fuel driver with adjustable settings (including a drill setting) to make sure I don't damage anything. It will be tough to get the door nuts off with it due to size but a right angle adapter would take care of that
It should be safer than a drill (depending on setting), and definitely safer than an impact. You can get some that are rated as low as 30 ft-lbs of torque. If you need more you can normally use them in manual mode to tighten up or break loose.Would one of the cordless ratchets (ryobi, milwaukee, etc.) be safer than a drill or impact driver?
How could you scratch the paint?I use my regular Ryobi driver. I keep a roll of painter's tape under the back seat and put a piece of it below each door hinge bolt when removing or replacing the bolt so that the rotating driver head doesn't scratch the paint.