To reply to some of your points in no particular order.
Underdark/Overworld position and relations:
The Underdark used to be a lot harder to access back in the day, and some DM's were very harsh on people who came down there from above. As a result it was a ghost town. The oldschool crowd might not like the more skullport-esque setting of Andunor but I for one quite like that it brings such large groups of players into the underdark setting.
Player Housing, Locks and Factions:
It is possible to break in to player housing, but it takes a lot of dedication. Personally I think that's for he best otherwise low-STR characters get screwed on safe storage space. As for guild houses, there are quite a lot but they are very popular. If you believe a particular group of people are sharing a property back and forth between themselves feel free to report it to the DM's, it probably falls within the muling rules.
Dungoeneering:
I advise that you start exploring some of the lowerdark and other endgame dungeons, because some of those are truly long slogs of tedium. Abyssal wastes and lost desert will be right up your alley if you prefer walking around for a long time instead of being able to lense out on demand.
Loot and Gear:
We used to have a system for spawning 'artifacts' in some hard dungeons, only the problem was that the very best artifacts were hoarded up and never let go of. Even if you make them non-repairable that just means casters get a free pass to keep theirs forever while melee's have to keep a set of theirs to swap in/out for hard encounters/pvp. It also irrevocably messes with the server balance. If Jimmy-epic-man whose character has been around for 10 RL years and got a full set of legendary artifacts equipped on him that are completely out of reach for a new character, even established characters, isn't that a little unfair to everyone but the most hardcorest and oldschoolest crowd?
Racial Requirements, AA:
You said it yourself when you described dwarven defenders. An Arcane Archer isn't just some guy who can make magical arrows, it's the culmination of elven dexterity, archery and magical culture and craftsmanship come together to make the perfect archer. It fits right up the elven class fantasy of elves being the very best at archery.
UMD:
Had it been 15 years ago, removing UMD dumps might have worked, but if it was done today you'd have to essentially rework the entire server from ground up as everything is balanced around them. Casters would have to be further nerfed, mundanes buffed in other ways, all dungeons and mobs server-wide have to be rebalanced or outright overhauled. Heck, even some puzzles probably have to be changed. A lot of work in the name of 'balance' when things are at a fairly balanced state right now with UMD as the balancer.
Summons:
First off, Dragon Knight is one of the better epic spells. Drop one of these on a boss or in PvP and it'll clean house for you.
Secondly, if summons weren't strong enough to let a caster solo content like a melee can, then what? Force wizards and sorcs to attach to parties where they do nothing but buffing their party-members and sometimes once in a blue moon drop a missile storm?
Palemaster:
I actually agree completely here. Palemaster is one of my favourite classes and I really didn't like it when it was first reworked all those years ago. I still don't like the direction it's gone in even though it's far, far better mechanically than it was before. I know it's a lot of work, but if palemaster got back their old summons that scale up regularly as they level and had those changed to fit Arelith standards I'd be a happy camper because it'd put Palemasters back as the supreme undead summoners.
