Wasn't aimed at me, but here's a list of things to add/improve/change:
1. The font. Kerning and letter thickness should be uniform.
2. Addition of ReplayGain. iBasso have said that they aren't looking to add this soon - but it would be nice.
3. USB DAC functionality (supposedly going to be added next firmware update).
4. Ability to scan the SD card manually (add a button to the settings menu or something).
5. Option to remove the on-screen buttons, making the cover art take up more screen space (with physical buttons, I don't see the need. Worth keeping the scrollbar, however).
6. Option to manually select how far ahead each jump goes when using the 'next track' button. Currently set to around 10 seconds I think.
7. Proper playlist management system, as well as a way to export it to the SD card so it isn't entirely wiped when formatting/updating the system.
I'm sure I could think of others. Out of my original list of around 37 problems, only 4 remain. The others I didn't really consider problems myself, but would be nice additions. I would suggest trying to increase the responsiveness of the player to the physical buttons, but as I'm not knowledgeable in that area, it could be unfeasible (this is a relatively minor complaint).
I think your above functionality are all stuff I would like to see, not sure about Replaygain, I am not even sure what that is, let me google it.
We should petition iBasso en masse by sending them your above list and ask them to work on those instead of providing their own project agenda. It is more likely to hit them than the head-fi thread, just my thought.