For such a small tool it need not be. If the mirror was larger, and subdiameter tool was say 6 inch, channeling might help. But it is not necessary. It can be wire mesh pressed (microfaceted), but not even that is necessary on 2" tool. Be sure that edges are scalloped, though (otherwise the tool might "dig in")
> 2. Is it pressed like a full-sized lap? If so, on what area of the
> mirror is it pressed?
Absolutely ! Good pressing is always necessary when tweaking optics. The difference in radius across a typical amateur mirror is so small that it doesn't matter at all where the pressing is done. A 36" f/3 would be different matter ! (in that case you'd have to press on the zone that you plan to work on, and radially support the subdiameter tool to prevent it from rotation - a trick from late Bill James)
Bratislav