I've heard that Stendarr and Boethiah have some sort of connection? as in some kind of positive interaction between the two? I heard it was mentioned in Daggerfall, which I've not played, anyone got any info about this?
Stendarr and Boethiah are allies. I have a bit of a theory as to why. Mutual enemies in Molag Bal.
Molag is the opposite of everything Stendarr is. Corruption, tyranny, domination etc. Yet they share an appearance somewhat. Molag Bal's "creature" is the Lion. In Oblivion he's offered a lion pelt, in Dawnguard his shrine somewhat resembles a lion's skull, and in a book in Morrowind he's referred to as 'The mighty lion of Evening'.
If you look at Stendarr's stained glass window, he looks very lionish. Boethiah sees Stendarr as besmirching Molag's sign. Acting opposite to Molag while appearing as his creature. Boethiah hates Molag Bal so anyone going against him is their ally. "Enemy of my enemy" almost.