I want Blizzard to see ideas and make them WoW's own, not implement them as they functioned in those other games.
I would however like it if tokens for character services, pets and mounts became a thing, not sure if some other game has that. I wouldn't mind if we could have the gold pool of our accounts across all characters (serverbound ofc) and same with the reagent banks, with easier mor convenient ways to transfer gold between servers.
Oh, and I want the "max 50 chars per account" to span across all servers, not having it be restricted to 11 chars per server.
One thing I know I'd absolutely NOT want, is GW2 fast travel. WoW having ground mounts, flight masters, SOME portals and different aircrafts/boats and flying mounts = part of the immersion of this game.
Which is easily countered by also having relevant content out in the world. This old trope is as tired as the "flying ruins the world"-crap that people spout even through expansions like WOTLK and MoP...
Optional Player housing would be just that, optional. It shouldn't be, like Garrisons, where gathering and shit is done.