(Sorry in advance that this turned into a novelette!)...
And who are these "many others"? Because, as it stands now, you appear to be the only person who believes that special moves added balance, when anyone who actually PvP'd back then and didnt hide in trammel all day long will tell you special moves threw everything out of balance.
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People want T2A to be the main era for the classic server, with appropriate fixes and patches to correct some of the old problems the game had, nothing more. They dont want a boondogle hodgepodge frankenstein patched together with stuff from all over the place.
UO:R PvP brought more viable templates to the field. I think hally mage duelers prefer that specific T2A era with insta-hit and precast, because there was some level of skill required to prevail, and because of effective combos that had a decent chance of quickly doing major damage to an opponent.
But for most of T2A there were no runebooks or potion kegs, which came in as a part of Cleanup Britannia. There was no secure house trading gump until towards the end of T2A, which was a detriment for someone wanting to purchase a house back when the prime spots for big houses were all taken. At one point, house deeds could be stolen, which meant someone could work for weeks or months to acquire an expensive house deed only to have it stolen in a second in the carpentry shop. (Fun for some, I suppose, but not what I would consider a welcoming environment for the general population. Some mechanism needs to be in place to mitigate that kind of imbalance, and newbie house deeds served that purpose.)
T2A didn't always have insta-hit and pre-cast. In the beginning of the era, archers still rocked, only to be nerfed. Tank thieves were nerfed. The era of the hally mage being the (slightly) overpowered template was born. But all that really happened was a few overpowered templates were replaced with another overpowered template. (And the 5x+2 mage and 5x+2 dexxer cookie cutter templates became prevalent in people's minds as the best way to compete.)
UO:R PvP might not have been balanced, but it did open up more viable templates. Alas, it also brought more of a luck element into PvP combat, which could have been brought under control by more stringent penalties to using special moves and having all special moves be player controlled.
But what you really are saying is that YOU want a classic server with the specific era that YOU enjoyed the most, and not that "people" want that, although I pretty much agree with you that a majority of PvPers might favor mid-to-late T2A with insta-hit and pre-cast. But UO is not just a PvP game. Some of the changes made the game less challenging and fun, IMO, but they came about for a reason, and that reason was the imbalances in the game that allowed a small minority of players to effectively disrupt the playstyles of a majority of players without real consequences, or with consequences that created different problems. (Stat loss encourages ganking of easy targets and running from battle, for example.)
Personally I prefer pre-T2A, before the anatomy and meditation changes, because that's when I had the most fun, lol. A slight nerf to archery and that would be my preferred era. But I figure I'm in a minority on that one, so my second choice would be the UO:R era (fel rules) because it opened up more templates. But I'd change the way special moves were implemented, allow pre-cast, and get rid of insta-hit. In a world of faster computers and better Internet connections, players should be able to outmaneuver an opponent's swing. I wouldn't be overly concerned with a combat system that favored cookie-cutter templates or preserving what was enjoyed by a small minority of duelers.
Concerning custom houses, well, I don't care, but in reading through the message boards, apparently enough people do care to have multiple accounts for their houses. I think that feature alone has helped keep UO alive so that we would even bother to have this discussion. I don't have a problem with custom housing -- it gives players an outlet for their creativity -- and I'd prefer UO:R housing over T2A housing, strictly for the expanded number of choices, some of which I thought were nicely implemented. (Small towers and log cabins come to mind, although I had friends who really enjoyed their villas for some reason.) So I say yes to UO:R housing, as well.
Another advantage I see with using UO:R as the base rule set, with fixes to special attacks, or perhaps their removal, is that if the classic shard proves to be a winner, assuming there is one, then it seems logical to me to open a Trammel version on a different shard. I suppose it's possible to open a T2A shard with Trammel rules, but if the code base from those eras has been preserved then I think it would be much easier to separate UO:R into different shards than it would be to put the Trammel rule set into the T2A code. (Sure, Trammel exists on today's production shards, but there might be as many players interested in pre-AOS Trammel as pre-Trammel UO.)
I suppose at this time I should mention what I would really do if I was in charge of the game. As much as it pains me to write this, if I did go through the trouble of developing a classic shard with basically a T2A rule set, or with the UO:R Fel rule set, then I'd kill off Fel on the rest of the servers IF the classic shard attracted enough players to warrant opening up more than one shard with such a rule set. That to me would be strictly business, because I think that Fel would become very empty rather quickly if a classic shard proved successful. The server resources and developer resources would be better utilized for what's attracting the players.