I found one person in PvP that hit me with two rockets in about 2 seconds. I couldn't understand why his rocket launcher reloaded so quickly. This would explain it.
If you are on PS3, no, you do not PS+ to play with friends or online in general. On PS4, I think you can play through the storyline by yourself without PS+, but if you wanted to play with friends or with other people in the Crucible, Stike missions, or Raids, you need PS+
I've had this issue. I didn't realize it until I was in a game of Battlefield 4 when I started shooting and no vibration was felt. I thought it might have been my controller not being charged, so I turned off that DS4 and signed in with my other controller. That seemed to fix the problem, but I guess using the same controller would have sufficed. I hope they fix this soon.
The thing is that we shouldn't have to mute, or go out of our way to ignore people who "cyber bully." If people could just be mutually respectable instead of questioning each other's sexuality (i.e. fag), then i might put my mic in and actually talk.