I've reported quite a few players before for team kills and being AFK. I think the only effect is has, is that it gives you some sort of satisfaction. Eventhough I dont think WG ever does anything with the reports, unless maybe the reports reach a certain threshold.
As for turning blue, it seems that will only happen if you kill multiple friendlies. I dont think it ever happens due to repeated damage. I did happen to turn blue on one of my games though, when I got 2 accidental team kills within 5 games on my batchat. The first was an accidental hit while snipping long distance with 2 tanks face hugging eachother, one of my shots strayed, oops. The other game I was trying to save my object TD from an amx and he turned right infront of me as I was taking my shot, oops again, now I was blue. At least we won both those games, and my teammates didn't shoot me up when I was blue. I apologized both times at least.
I got in alot of good games friday and saturday and ended up with a 65%+ win rate. However Sunday was a whole nother story. I platooned with my brother in the morning (hes a good player) and we just couldn't win games to save our lives. Every match XVM had our odds in the 20-30s range. Seems like all the idiots were always on my team. Ended the morning with around a 42% win rate, I did get in some games that afternoon and was able to pull that up to 53% by the end of the day, but thats still not where I want my win % at.
I think half the problem was that I couldn't get my double on my E-50. The fact that I dont have it upgraded means its like a tier 7/8 in a 9 slot. The hull has decent armor, but without the upgraded turret, the turret armor is laughable. Not to mention the gun is the same gun my tier 7 TD has (and the TD reloads faster), 203 pen and 240 damage with like a 6.5 sec reload. It just doesn't cut it in tier 9/10 games. I would have to spend around 100k free xp (which I dont have atm) to get the tracks/turret/gun to make this tank worth driving. Unless the tier X variant is worth a damn in 7.5, my E50 days might be numbered.