I think that would be a nice idea. For example, if I want to go see my Daggerfall Covenant friends while I'm in Morrowind, I'd just have to hoof it there, or maybe get a horse-and-cart.

I think this would be a nice idea, as you are completely free as a player, but when in another area, you need to be careful, and also you need to explore it properly.

I dunno about the rest of you, but I'd like this...

I would agree. It would be silly if one wouldn't be able to go to e.g High Rock even though you are no member of the Daggerfall Covenant. But I agree, there should be no fast travel there; that would make it too easy.

+1 for this idea.