I've been doing models for about ten years now, starting with Warhammer and Battletech. Since then, I've done a hand full of other games as well with AVP being the most recent I've started to collect.
With that for context, I'll also add that I'm a mediocre painter of models at best, but have moderately large collections of most everything I play.
For glues, I've tried a wide range of glues, some expensive, some cheap, and when the day is done, there really isn't a huge difference between everything I have used. My personal favorite is to just buy the cheap gel superglue. Its got good strength to it, it stays where you put it for the most part, and the thickness of the gel can hold smaller pieces in place before they've dried if you're careful with it.
For spray paints, it DOES seem that the brand name stuff is a little better than the cheap stuff, but I still make use of the cheap spray paint. I just have to be a little more careful with it to avoid using too much. Just a really light layer, barely a dusting seems to work best for me. Sometimes it takes two coats to cover everything correctly though if you're concerned about the paint filling detail. On the grounds that I tend to be very gentle with my models, I couldn't tell you how easy it is to scratch paints off of your models though, so for the spray paints you might want to ask someone who plays competitively and transports their models regularly as they are the kinds of players who are most likely to know what's going to work best on that front.
The new advantage of the plastic materials leads to the questions if there are possibly
recommendable merging (?) glues and base coat sprays available around on the market!?
Im of course meaning those stuffs which just cant be scratched off because they sorta
melty their layers with the model surfaces .. .