Hello again!

I am writing a guide book for travelling dunmer traders, envoys, and diplomats and my question is would house temples instead of full blown temple complexes in foreign provinces be acceptable to the Tribunal?

I don't see why not. They use house temples to venerate their ancestors already.

To give you a better answer, is this before or after ALMSIVI died?

This would be shortly before TES III so before.

Would the head of a house temple need to be an authority figure like a priest? Or could anyone orthodox conduct services?

I'm going off of what little I know about Roman practices with the Lares and Vestia and such.

A private shrine for veneration of the ancestors and ALMSIVI should be enough, no ordinations, just a daily prayer or ritual.

Whether the Temple approves or not is up in the air (I'd say they really wouldn't care).

I doubt Vivec would mind. He claims he even loves the ancestor worship of the Ashlanders.

As for what the Temple thinks - which was largely out of the Tribunal's control as of the events of Morrowind - it depends on the Priest in question I suppose. I guess most wouldn't mind much, although some might accuse you of heresy or witchcraft since the Ordinators seem to be getting very over zealous as of this era.

It kind of reminds me of that episode of South Park where Jesus appears and Phil Donahue says "Who are you to tell me what to do? I'm Phil Donahue!" That seems to be how most of the Ordinator captains feel about what Vivec likes, sadly.