Now finishing the board design in KiCad. I will share the project in the end after it is tested. The list of changes is under "Read more" link.

Meanwhile, check out my tutorial on DIY PCB assembly here:

Instructables: How to Assemble a PCB With Tiny SMD Parts

1. Changed GPIO expander from SX1508B to MCP23008T, which is supported without rebuilding the kernel.
2. Selected more DIY-friendly IC packages for the expander and the USB switch.
3. Corrected board dimensions to exactly match the display.
4. Removed unnecessary 0-ohm jumpers.
5. Added capacitors near host USB connector.