Yeah, I'm pretty sure the character limit is 2 per server. It's a bit hard for be to be sure since I had 8 characters on the account from one of the free weekends last summer. Even after the game went F2P I had access to them all. At least up until Novermber/December-ish when they started enforcing the character limit and most of them got locked out. It was at that point I upgraded to "preferred" and the limit jumped to 6 per server. I spent most of the coins on the two extra character slots I needed and the rest on legacy rocket boots. I've since added a few extra slots by buying the unlocks on GTN. I'd have done that from the outset but I didn't realise the character slot unlock worked across all servers.
Out of curiosity, what is the approximate CCs to in-game credit exchange rate? I really want to get that artifact unlock, but i have no intention of spending any more real money on it. I figure since nobody is likely to put it on GTN for a sane price, I need to find a sub willing to trust me enough to pay them in instalments and wait while I regenerate my cash reserves.