I don't care much about 16 bit color text, math commands (except maybe modulus if the calc lacks it) and a mouse cursor, but I would like the others, especially 1. As for file copy, what I would like is the ability to copy programs from storage memory into RAM and be allowed to delete the RAM copy later. This is essential for large RPGs like Illusiat 12 and 13.
In others, I would like the following:
-A replacement to Line, Pxl-On/off/change (although I guess rectangles could do the job) and the graph screen text commands, that does the same thing, but allows more colors and runs faster.
-A replacement to Locate that actually works with non-ASCII chars, unlike the built-in command. This could be solved with a correlation-like utility, though.