Yes. I use it for all kind of little imperfections on my prints. Together with some metal piece with a small flat surface (e.g. flathead screwdriver). So I can warm it up and smooth it out a bit. Very thin stringing is gone like instantly. As it gets bigger, you have to be careful and patient.
No, I do torch it directly. I use a screwdriver afterwards to form it the way I want it. And a normal gas lighter always leaves soot residue you should avoid to get on your prints.