1)  It's the go-to for me.  PvE is fake PvP.  PvP is the most prolific and most reliable source of player-driven content aside from RP.  Since RP often takes time to set-up and can be littered with shitters, PvP is the easier choice when trying to quickly access player-driven content because the mechanics of PvP are infinitely simpler than RP.

2)  Power Creep and objective reasoning of gw2 mechanics degraded my experience from good to very bad over the course of probably about 6 months.  It probably ended up starting when I started ranking into higher-end matches.  I didn't really change my build that much because I was having fun, but eventually my build became obsolete in most PvP scenarios because the meta changed as I ranked up.  Skill shots (i.e. casting Magnetic Aura on myself and body blocking between a longbow ranger and the ranger's target that isn't me) can raise the enjoyment, but they're scarce in the game and can't improve the game on their own.

3)  I'm pressing 2, 5 or E.  It's nothing to write home about.  If anything, I feel depressed that people aren't able to kill me given that I'm using a typically underpowered build in the context of meta gw2 PvP.  That's the real issue:  whether you're playing “well” or “poorly” it doesn't truly matter because gw2 mostly plays itself for you.

4)  It's frustrating, but the game is just rock paper scissors, so I try not to let it bother me.  Everything is quickly and specifically explained, and despite the game's general simplicity, the frustration remains because it's often impossible to deal with certain players in some situations just because the game is designed to work that way despite the fact that the victim can read the opponent perfectly.  It's also the reason why I don't really play this game anymore.

5)  Yes to both.