In regard to (3), I guess that I can't say that none come with multiple adapters, but I have not seen a suppressor that comes with more than one. Adapters are not inexpensive, so make sure that you enter those into your calculations. I bought three additional adapters for my first suppressor. Then I figured out that while logical, using such a thought process would discourage me from buying more suppressors. That's not good. Plus, changing adapters at the range takes away shooting time. Suppressors get hot, so you have to wait longer than you'd think. I personally recommend buying a separate suppressor for each cartridge/thread pitch application. If you buy a 45cal suppressor and want to use it for 9mm and 10mm, you could end up with five different adapters: 1/2x28, 1/2x36, tri-lug, M13.5x1LH and .578×28. The first four are for 9mm and the last is for 45ACP and 10mm (I think, check your barrel threading).