Sometimes we are looking for items (specifically weapons) with certain innate property, or to search items that are only droppable by monsters, and search items which are also buyable in NPCs.
Maybe it's a good idea to include in the search items by:
Droppable, Buyable, Property.
On the other hand, is it possible that the RMS could also expand Skill search just like what you did to the Item Search?
Search by ID, Name, Type (active/passive), Class (1st,2nd,3rd,Trans), Description, Selection (self/player/enemy/area), Max Level, SP Cost, Attack Property, Cast Time, After Cast Delay
(Note: I didn't include Job, since we could just go to skill database and go to the skills DB of each Job)