I've even had pro's ruin panels. I don't know, I think it is more about what material you use, but sand is a no-no. There are a couple of guys on here that know a bunch about the subject let's see if they respond.
On the stripper,that I have done a ton of and have a few tips. The trick to stripper is you simply mask off what you don't want it on just as if you were painting it. Here at work we will strip the roof of a year old car leaving not a mark on the rest of it, simply my covering the car in plastic, exposing the roof by cutting it out and then adding some masking paper over the top around the top just for good measure. After it's stripped being very careful to peel the paper off as to not touch or drip it on the car and wham, done deal bare metal roof.
Seams and such you always want to cover with duct tape then after it's stripped you remove the duct tape and remove the paint and gunk in the seam with a surface conditioning disc .....
Or a "clean and strip" disc.
They work WAY better than a wire wheel.
But this is the norm, to cover up what you don't want stripped. I have even done complete cars that were assembled (no chrome and handles and stuff though) where all the door, fender, hood, trunk seams were duct taped and any other holes like antenna and handles and locks. Then remove all the tape and sand off the remaining and wham, bare metal car.
One thing I can't stress enough, if you can't really jump on this car and knock it out in a day and sand it and get it into epoxy primer I HIGHLY recommend you do a panel at a time. It takes a little more time but you don't get overwhelmed. it is VERY easy to be overwhelmed by a bare metal car sitting there. And you just can't walk away until you feel like it. So doing one panel at a time getting it back into epoxy primer then moving onto the next is a recommendation.