I use 5A or 3A (between 5A and 5B). I rarely break sticks; they get whittled thinner over time until they sound weak, like smaller than 7As.
Nylon tips. Used ProMark for 30+ years because they guaranteed the tips didn't come off- and to be fair, they haven't, although I have a couple of pairs now that the tips freely spin, which is disconcerning- but they've discontinued my preferred models, so I'm on the hunt for something similar. I'll probably go with Vater Fusion, but I'm a bit stocked up currently.
I've had nylon tips fly off some ProMark sticks, but that was several years before the aforementioned guarantee began. It's also been over 30 years since I've broken a stick- a Vater 3A split nearly in two.
Re: glue- what sort? I tried that early on with the aforementioned ProMarks, with regular super glue, but it never lasted long. Re: switching- same, except it's for chipping from edges of hats/crashes. (This doesn't happen quickly- I don't strike at an extreme angle. Good technique. /humblebrag, lol)