wo wo wo wo wo, buck up soldier. everybody has those days. just say you'll get them next time. dont worry about kills/deaths. if you do you'll just worry and get angry, sad, etc. just have fun thats what its all about. the more you play the better you'll get i promise you that.
my best advice is to just play more and get used to getting shot. what i mean is when i first started playing paintball, i was afraid of getting shot so i wasnt aggresive. so i just played again and eventually it didnt hurt as much. and for your pod pack make it so the opening of the pods is facing towards the straps and facing toward the ground. it may sound dumb but it is a lot more effective. also open your hopper b4 you get out a pod (unless you have a speed feed)
it doesnt matter performance wise. unless your the kinda guy which likes to be unseen and sneak around then probably it would matter but otherwise. I have an A5 and i dont put a bright orange barrel on it i have a black barrel just cuz i hav ocd and i like my markers to match.
ive gotten little parts kits (orings, screws, detents, etc.) barrel bags, lube, manual, depending on the marker you can get a barrel kit. thats pretty much all ive gotten that i can think of off the top of my head.