I'm not suggesting the dwemer built them simply because i mentioned the dwemer migration westward and an example of how {whoever built the index} could have in theory migrated west also. AFAIK nothing in Morrowind other than the fact they are located in ancient dunmer strongholds suggests the propylon chambers were built exclusively by Chimeri. The point is the Lore is vague enough to plausibly have something similar in Skyrim.

Good discussion of teleport here but as far as the original premise goes, I don't think it's a great idea for a mod that makes a player spend dragon souls as a way to 'pay' for a feature that a player is not required to use and is added as a convenience option. Don;t like FT, don't use it. I beleive in you. You CAN fight the temptation to click that button, I know you have it in you.

Yeah, I do have self-control, and even if I didn't, I could grab the No Fast Travel mod. That's not the point. The point is that I think it would be cool if fast travel were still in the game, but made to have a much higher cost than it has in vanilla (i.e., more than nothing), so that it is something that you have to save up to occasionally do, rather than something you just do willy-nilly whenever you have a quest to get to two minutes' run away, etc.

Think Dragon Souls are a bit much though. I know I'd never bother fast travelling with the new system until I've collected all the core Shouts.

What about just slapping on a really long cooldown to the Wings of the Dragon shout you had in mind? That way teleporting out wouldn't be a problem, but teleporting in would come with a bit of risk because you would be shoutless until the timer expires.

Edit: And if you want to limit it further, you could have the first shout be the one that binds you to a location and the second one a shout that actually teleports you back to it or something.

You know, if you're going to make it a shout anyways...

MQ Spoiler!

Well I was just describing how it was in Daggerfall. I never said winding up dead while fast traveling was a good idea (I was thinking how annoying it can be when I wrote that). But I like your idea of having to fight off enemies at random spots along the way. As for how this can be done, I'm not entirely sure. Maybe a way for the game to detect certain points between locations where fast travel can be interrupted and spawn the enemies? Something like that could actually work with (quite) a bit of creativity.