My votes:
-Pretty much everything except multiplay scenarios, new terrain and new great leaders are priorities.
-Austria (Austro-Hungary), Carthage, the Dutch, Korea, the Mayans, the Ottoman, the Portuguesse and Sumeria (ie, 50% of the PTW civ list, and 50% of the C3C one)
-Egypt, Ramesses II, Rome, Marcus Aurelius, Greece, Pericles.
+Japan: Meiji. (MUCH better than Hirohito) The other choices all belong to civs that have 2 leaders already, and I'd rather they up the leader count for those that need it.
-Naval units for the classical (galleys were WARSHIPS, not transports! Just because (some of them) used boarding as their primary tactic doesn't mean they were transports!), Renaissance (no, galleons were NOT slow transports - they were very much the combat-able ships!), 18th-19th and 20th century.
-Cruiser as most needed units.
-Naval units (all of them except possibly caravels) should be able to destroy tile improvements in adjacent land squares, to make fleets more important. Barbarians should spawn such naval units.