Newest hurdle: marking things as dirty for re-rendering.
Suppose for a moment that you have a keyword, say Rogue. You add that keyword to several squadrons. You then give Rogue a new icon. Now you've got to re-render all cards that have Rogue as a keyword. Ouch.
That's bad enough, but suppose that you've got a Genre and you set one of the custom colors for that genre, but it's only used in 1 renderer and 4 squadrons for that renderer. I've got to figure out how to make it only re-render those 4 squadrons without re-rendering every squadron that uses that genre.
This one may be painful.