I don't understand. I am not experiencing the majority of these issues:
Frame rates in WZ Fleet are just fine when I put shadows to Low. I have a pretty beefy machine, and anywhere, in any MMO, when you get allot of people together, you are going to get slowdowns due to shadows. It's just how it goes.
I have noticed this, but it is minimal to the point I don't notice it very often. It does not keep me from being very successful in WZs.
Only graphics glitches have seen out of every planet is when I am able to venture outside the limits of the intended play area. And that is completely understandable.
I have had so much more success in WZs since 50s are in their own bracket. It's actually fun again.
Have not made it to HMs, or have enough people in the guild to 50 yet to do a raid.
This must be something you, and a select few others, seem to be experiencing. I am sorry for your current situation.