yes, if you are using trunk (2.3) you can use a higher brush count as you could use if you would use 2.2.x
and we really need mappers - if you have questions join the irc and talk to Richv or me - you can also read the wiki tutorials. but it often helps to ask a specific question and getting the answer right in the discussion - so use irc
would be nice if you could create some maps for the game
hope to hear back from you (many people lose track after trying to get into mapping)