thorian
Explorer
The most important thing to be careful of when dealing with a Dweomerkeeper is, as Thanee mentioned, the class ability they gain to convert a spell into a supernatural (Su) ability. For example, by the RAW, a dweomerkeeper could cast permanency, limited wish, and wish without paying the XP! That is why people are suggesting you house rule the inclusion of XP, even though (Su) abilities don't require spell components. Other things to watch out for are spells with expensive components. These are not as easily abused, but you may want to keep your eye on which spells he converts to (Su).