How about you svck my balls? isnt that a better idea?

Nanosuit is just a troll. Ignore him and he'll slowly go away.
On topic: I believe the suspressor actually decreases damage. But maybe it's because it takes longer for people to realise they're getting shot at? Honestly, I don't know.

I didn't notice it decreasing damage, but it does add weight to your weapon making your mobilty slighty slower. It is pretty negligible either way. Use it and you won't be dissapointed.

It depends, if its the Feline w/ Suppressor, i say it kills faster because it has a high fire rate. Sniper rifle with suppressor is still a 2shot kill and the Scarab w/ suppressor is a little weaker but bursting your shot would help with you kill with less bullets wasted.