I'm fairly new to the cars 5'8" 13 stone, but it has taken me a while to figure out the entry / exit procedure.
To get in, I kind of bend my left leg on the seat and slide into the seat while putting my left leg into the foot well, then manouver the right leg in. I have found this much easier on my back and probably the car seats as well.
Getting out, right leg out first, then sort of slide out with my hand on the rrunning board, mind you this is probably rubbing the side of the seat as you describe, but no damage so far.
I treat my seats to a very light coat of Gliptone leather conditioner every couple of weeks. I really like the new leather smell from this product and it leaves no residue after application. I also do this on my other car and after six years the seats are still almost as new.
