I do have an issue though where when I start up the game I can't choose my victory conditions:
I can't think of why the game rules are not available.
I think this might not be a problem with WW per se, but (yet another) Civ3-bug, similar to the World-size/Culture-limit bug. If
@DBD175 played another mod before starting WW, the previous mod's victory-rules
may have been imposed on WW.
I (think I) saw this happen one time with Lord of The Mods: I'd been playing the Firaxis Fall_of_Rome Conquest previously (which uses the "Elimination"-mechanic), and when I started LOTM, I (realised later that I) still had the Elimination-option switched on (not sure that it should have been). Although I'd seen a few "The XXX have destroyed the YYY" messages prior, I didn't realise that it had happened so
easily, until the first war of expansion that
I fought: the first AI city I captured, made the rest of that AI's towns go boom as well ("All too easy...").
IIRC, when switching between mods, to dodge the bug you need to start a normal (epic-)game first, then quit back to the start-screen,
then start the mod. For any subsequent games with the same mod, you should be good to go.