1. End drain works best with more than one player doing it, and/or have -recovery(see Poison). End drain by itself via a single character is underwhelming. End drain on minions and LTs is fine. It's anything higher where issues start to arise.
2. Elec's damage is on the lower side. As Yomo mentions, any damage increase via debuff or buff really would also be true for any other set. I haven't looked at IOs for it, but adding some procs could help, but again, it would also do that for some other sets.
3. It's okay.
P.S. Partly because I paired it with Kin, I found Elec/kin controller a far superior version as the defender version was my main on Live. I didn't recreate it here though. I went controller and then axed that at 41 although I might reroll at some point. /elec is simply a lower-mid set although again, I used it as my main so I enjoyed it enough.