The End shouldn't be PvP because we don't need two PvP worlds, we only need one. Two PvP worlds would make things confusing. If it's necessary maybe the new portal could have a PvP end while the former Aether portal is the non-PvP end.

Maybe with the End, we could have a bit more Endermen spawn, as to make the End a harder place, and to make an easy way to collect Ender Pearls for people without fly.

Mining world is meant for general mining
Nether world is meant for PvP, and also mining - at a risk.
End should be a place to gather rare items and explore the End Cities.

 

Delete PVP world. Its DEAD, when 1.9 was released I asked people in global to come test it out with me, 80+ people on, I spammed it in global to get attention eventho I know It'd result in a verbal warning. Still no one came. ITS SO DEAD. It cant be fixed, if we want a pvp world we just need private arenas with commands like /Challange [USERNAME] then those are private matches, and if ur in a mcmmo party u can challange other partys. thats the only way pvp can be revived. It'd also need to be a world with no MCMMO bonuses as they are overpowered to new players.
If that doesnt get added.; Just delete the PVP world, additionally vanish should be disabled in End/Nether, making it a whole lot more interesting, Things should randomly spawn in the end/nether , worth a fair amount of money randomly, to keep them active.