I imagine they would.. there was just some talk about which ones worked and which ones didn't, so I just posted what did/didn't work for me.
Yes, one (All I've tried is one..).
Like I said before, I got a mod that required both Bloodmoon and Tribunal. Tried it, didn't work. So I opened it up in a hex editor, and replaced both bloodmoon.esm and tribunal.esm with morrowind.esm, then tried again, and it worked (It didn't just load, it worked).
And no, I don't remember what one it was. It was just the first one I came across on Morrowind Summit that required both expansions.
I'll have to mess around with them some more later.. Make sure it wasn't just a fluke or something.