Nemesis have escort missions, mystic boxes, and RP mobs. That's plenty enough to keep ya busy PVEwise. None of those activities you can benefit for the long run tho.
In terms of solo leveling, nemesis is where the fun ends. I suggest using those minor exp boosters to get the hell outta there and proceed to Ellis (lv50+).
Pvp in this lv cap used to be good enough a year an a half ago. One day they realize that in order to funnel people towards endgame, everything fun in lower level caps must be tuned down. And so when admin decided to kill lv55 NB, pvp in nemesis and ellis died along with it. I still have my lv49 sw in FK tho. I promise to sign up for BG if I ever log in that toon.
Nemesis aside. There is no shortcut towards lv65. It seems like they cant increase any further exp gained from mobs. If that's the case then why not instead greatly decrease certain mobs' hp and shorten their respawn in DV?