You can be friends with them in the dark. If you have dragonborn dlc you can be really good friends with one if your a smith.

Ahoy!

If your character is meant to be an ally of the Thalmor, then don't be killing their Stormcloak tools. Your character should align with the Stormcloaks against the Empire. Your character should leave Heimkir alone as he is (trying) to help (unknowingly most likely) the Thalmor cause.

There is a Thalmor faction at Northwatch Keep, but they will treat the player as a potential trespasser.


Cheerio.