Suggestion: Add the ability to write to all the enemy/item editor variables, and attributes; and to the link vars, and attributes, such as Link->Tile. This would go a long way to making multiple player-characters viable.
A far larger number of available tile pages (for 8-bit graphics quests), custom palette definitions (rather than CSets), and a huge max DMAP/MAP count would be nice for 2.60.
By custom palette definitions, I mean being able to manually take swatches from a palette, and arrange them in any desired order, to make a 'custom CSet'. That would allow more diversity, for 8-bit graphic design. Otherwise, tile page caps constrain you out of options rather quickly.