I'm hardly an expert but I do know the answers to your questions. Do note that I am only experienced with BPs and the answers aren't always the same.
A. While they can get used to being held and snakes that are held often are generally friendlier and are better at being held, they don't particularly 'like' it. I wouldn't say mine dislike it (sometimes they do, during shed or within a day after eating) but they are pretty much just fine if they are left alone. So, I don't think you have to worry about upsetting Monty when you hold him, see above exceptions, but if you leave him alone for a long time he probably won't hold a grudge either. BPs are cool that way.
B. There is such a thing as too big. BPs tend to be agorophobic and some of the more picky eaters may go off feed if they are put in too big a space. One cure to this is to always give them a spot that they fit into snugly (a hide that the fill up, which is a pain when they are growing). Personally, I keep my juveniles in 15qt sterilite containers, as they get bigger, they live in 32qt ones. Some people keep adults in 32qt. and I don't think there is anything wrong with that. Mine go to an even bigger size, 41qt. They don't need a lot of head room as they are not arboreal and I found when I gave Syd a taller tank for my own decorative purposes, he would constantly push up on the lid which was so high that he got off balance and would fall over, a little dangerous. So, hope that gives you an idea. I don't think any BP needs more floor space than a 41qt provides (sterilite.com has the dimensions of these guys).
C. There is no real reason to need to know the gender of your BP and determining the gender is more dangerous than not knowing it (probing and popping are usually perfectly safe but can cause damage if not done correctly). I guess if you wanted to house two together then you may want to know as mating could occur before a female is of a healthy size and two males could fight a little. But these guys are loners and less problems occur if you house them seperately.
Well, that's it. I hope you were looking for a novel because I seem to have given you one. Enjoy your BP, they can be great friends.
-----
1.1 Normal BPs (Syd and Nancy)
1.1 Het. Albino BPs (Bill and Beatrix)