If however, you meant the Merged campaign, only enable that if you have a fast PC (it will increase loadtime) or are planning to sail from the Atlantic to the Indian ocean, otherwise you won't really need it.
as to the TC issue, this happens sometimes the first time you run the game, don't ask me why, I don't know, usually it clears up the next time and you can go to 128x in the Kiel Canal, if not use sh3 commander
