Simple suggestion. When you've got pixels selected in the Tile Drawing screen, pressing "Delete" will turn all selected pixels to the transparent X color.
Simple, no? Very practical.
Deleting Selected Pixels in Tile Editor:
I'm still unsure what the selector tool is really intended to do in the first place.
But yes, that's a pretty useful idea.
Oh, I've been using it to select 8x8 selections of tiles for use in Relational and Dungeon Carving mode setup operations. It's extraordinarily useful. As a tile editor, I've grown extremely fond of it.
The selection area remains when you use Ctrl+Direction to switch tiles as well. 😊
That's a good suggestion, I doubt that would be pretty useful.
Also, I think we would need MSPaint-style cropping (moving a piece of the picture around) and the freeform crop tool, which would allow you to crop a piece of the picture looking like a key, etc.