a) No, unless the NPR happens to generate with the same number of research labs as you did. NPRs generated at game start are given whatever industry, military, and research is appropriate for their population size and government. On average I think they will have the same starting population as you, but there is a random factor that produce aliens both much smaller and much larger than your empire.
b) No, unless you increase the star cap at a later date.
c) 10 NPRs in a 20 system galaxy is going to be a very tight fit with lots of fighting. There will be 5-second increment NPR fights, but if no spoiler races are involved those fights will rarely last more than a few minutes at a time. It will be slow, but not unplayable slow.
5 NPRs should be fun, but I'd suggest no less than 5 stars per NPR to give a little breathing room between everyone.
Also remember that as galaxy fills up cross-linking to previously discovered systems becomes much more common. The smaller the galaxy, the earlier cross links will appear and more tightly nit the galaxy will become. The last time I played a quick-game like this I had 3 NPRs, no spawning, on a 60 star galaxy. By the time I established contact with everyone the jump map looked like this.
