Yes, vArranger is playing nice with a Touch screen

Not possible with SD card, as they tend to change what they are showing to the software denpending on the card reader and the computer. Only USB stick

The top note feature need to add a bit of latency, to wait a bit before deciding this one is the top note.

Midi is a serial protocol, and when you press a chord, notes are coming one after one in a serial line. The first coming can be the lower, and the software will consider it as the top one