[deccan]

If you have too much gold and too little resources for production, then you haven't spent enough gold building fortresses. Provinces don't get access to their full resource allocation unless there is a fortress in it. Plains, farmlands have the least resources but are the best for gold. Mountains have the most resources. Fortresses also suck resources from neigboring provinces, so a fortress in a mountain province surrounded by other mountain provinces has mega-resources.

I guess that you were playing Ulm which has decent xbowmen for Provincial Defense. However, in MP game, massed missile fire can be dealt with relatively easily and any flying enemies will carve up missile troops. Ulm is generally considered the weakest of the nations.

And no, all units need a leader type to lead them and can't move by themselves. They will rout if they are left on the battlefield without a leader. That's just the way the game works I guess.