yes a medic is pratical for a big battle or event, but not for regular use by a player due to him/her not recieving any exp for it, and unless a medic liscence or something of the sort (repair maybe??) is created, it wont be a common job, and have little value to the player themselves to play

and for pre-determined classes, that just removes most of the versatility of this game, which is the reason i joined, and more than likely one of the biggest reasons for many others joining, it and the twitch combat are what set this game apart from most other MMORPGs,