I don't have much to add in great detail, because balancing is difficult with all of the skills available.

What I will say is that I enjoyed PvMP the most in the first couple of years of Lotro. I'd prefer it to be balanced and for it to go back like it was before (With the Elf / orc camps at the original location). The Delving of Fror and the outposts were fine as they used to be in my opinion, but I don't know. I would prefer many weaker npc's instead of fewer strong ones in the keeps and towers, but performance is important for pvmp. If this is the only way to better it, then sure. Perhaps it's possible to improve your servers instead. It's not just a problem for pvmp, but pve as well.

Adding a new area doesn't work in my opinion (in case this is a possibility). Osgiliath proved (in my experience) that most players will stay in the Ettenmoors. Having a bigger pvmp area also means more land to cover on your character and the chance of running into players of the other side is lower.

I really like the PvMP of Lotro and it's different from other games. It's an original concept and I like the Ettenmoors map with its keeps, towers, camps and npc's. Personally I wouldn't want it to change too much, only for it to be improved. I think the main issue is balance. I'd be happy if you could at least improve this. To buff the creep side (stats, skills, morale etc.), so that it won't effect the pve content.