hey mate,
why does it worry you that they use donations to keep the servers running?
lets take Runescape for instance.. they have a membership side that i'm almost positive the money is used to pay for the servers and the free to play players have adds around the game, again more than likely used to pay for servers.
PRO is very small at the min and need any bit of income they can, it doesn't worry me at all as once the community grows so will the revenue and then it should become stable
anyhoo welcome hopefully see you in game