that thing that you mentioned about rom bases is becuase after the new tile is inserted in the tileset1 that is seen on advancemap will have them messy becuase theyre arent edited there that will i do when i insert them dont worry:)
and yeah the pallets are the trickyst thing in advancemap i neede really some time until i get how the pallets work really...at the begining i didnt even know how to change them so i inserted new tiles but used fr pallets and yeah the tiles looked very horrible than

but now i know how:)