3 feet is good. I wouldn't go less if you need to walk between them. I space mine 30 inches in a raised bed and it gets pretty full, but I can reach everything from the outside.
My first year too from seed and this is a hoot. Couldn't ask for more helpful folks around here. Good luck with your grow Paco
Do you have drain holes in your cups? The reason I'm asking is from all your pics your soil looks like it is on the damp side, if they stay wet for too long it can cause you all sorts of problems, yellowing, leaf drop, dampening off, ect. You have a nice start so far.
Well I am not sure the average, but I planted my two slow growers on 2-12-11. I planted 10 Bhut Jolokias and 12 CarRed Habs. As of today I have 4 Bhuts and 11 Habs. They were bought from CPI, I did nothing fancy (no soaking) They were planted in one 72 cell and sit atop a Hydrofarm germ pad hooked up to their thermostat. This is my first year so it may be beginners luck!
I am not at all an expert but I say start some new seeds.
I wish you the best.
Latest update my jalapenos and cayennes cross polinated a few plants. Nice tasting hybrids!