So the last time I had the issue that the Civ 4 Diplo options weren't showing up, grabbing the CBP and deleting the LUA folder from it fixed the issue. I recently updated to the latest files, deleted the LUA folders, and the issue is back again. No idea what's causing it.
EDIT: Downloading the original Civ IV Diplo Features mod and copying its UI folder into the Community Patch's version of Civ IV diplo re-enabled sharing Maps and vassaling, but technology trading is still hidden.
EDIT THE SECOND: I'm an idiot, I had No Tech Trading ticked in the options, but everything else is still valid.
EDIT: Downloading the original Civ IV Diplo Features mod and copying its UI folder into the Community Patch's version of Civ IV diplo re-enabled sharing Maps and vassaling, but technology trading is still hidden.
EDIT THE SECOND: I'm an idiot, I had No Tech Trading ticked in the options, but everything else is still valid.