After awhile, the best (and probably sole) way to attract colonists is by using Psychic shock lances. When the base is large, and an army of many many people appear, I start scanning them to see who's better. It would be awesome to have a gui list that could show the enemies ordered by factor. The factor would be a sum of <enemy property>*<multiplier set in xml for that property>. For example, I would use a multiplier of 10 for the 0/1 value of whether the enemy pawn has "Industrious", and a -0.3 multiplier for the pawn's age. Per hediff multipliers would be cool, if too much work a 0/1 value of (has any kind of permanent hediff) would work, too.
I am *trying* to get into modding, so if someone can bootstrap this and then leave me with the laundry work to do, i'd be happy to.
Were you the person who asked about scoring people a few months ago? If not, you might see if you can hunt up that discussion.
I highly recommend http://rimworldwiki.com/ in terms of getting started in terms of a build environment etc.
--LWM