Can I still play the game if I don't own the tokens? Also, is there an unfair advantage to players that buy items with tokens?
yes, you can play the game even if you don't own tokens. No, all of the items you can purchase with tokens are cosmetic only and will not give plays an unfair advantage in game.
This is really important, since Skara aims to be a eSports/free-to-win experience. Using tokens to buy better gear for your character would be terribly unfair.