I've been shaving my pits for as long as I have my genitals. I prefer hairlessness! It does keep odor down to a minimum. Started this in the 1980's. Started to include my chest and stomach, now I have short hair on my head and forearms. The rest of me is smooth!
Yes I shave my underarms and have done for years. I don't remember why or when I started but it's just something I seem to have always done. It's the only bit of me - other than my head hair (I'm bearded though) - that I do keep shaved. I leave all my other body hair alone
No. It would be nice to reduce the volume to compliment my usual look of lightly hairy, but it's not thick enough to be a pressing issue for me. I don't like the idea of stubble from shaving or prickly ends from trimming. Plucking the longer, thicker hairs to leave only the shorter, thinner ones as I do further down, would be my preference, but the motivation factor is yet to overcome the effort to do it to myself.
I remember my first waxing of arm pits. I discovered how much less odor I had and liked the feeling as well. I had laser and it got almost everything. It look odd to me when men have a shaved or waxed crotch but full underarm hair. Personal choice do what you like for yourself.