Yes, protection from level1 in your homeland sounds like the best automatic-mechanism alternative, with an option for, let's say Council, to implement immunity to special roles that aren't homeland related. (Like Z with Bob the tree, rather than the whole No man's land)
For the immunity to start, perhaps you should reach a certain amount of land loyalty, before your homeland being able to trigger the immunity - perhaps 100 land loyalty (tops) - and it only working in your home, not for every land you have 100 land loyalty in.
MD has admins that usually keep care of what's going on in the realm, so they can pick up if someone grew an attachment to a certain location, for those special cases.
The only thing that makes me uncomfortable about that 100 land loyalty thing are players that are just logging in for days, and didn't really manifest an attachment for their home, to develop that attachment, being immune to teleportation there.
Perhaps a good way to test that volition stats? :)
100 land loyalty AND xx volition stats.
Development of levels for teleport spells would be kinda cool, because distribution of those spells to players would be much easier to make now when in doubt, rather than just give it and hope that it won't get abused.
High level teleport spells should be REALLY rare, like 1 or 2 people, that have something very specific in their roles that is pro-teleport, or are just known as famous wizards.