Welcome @ttxtea I am responding as a user so some info may be incorrect.
First charging % It took the controller for mine about a week of cycling the batteries before I hit 100% charge. about 4.1V per cell.
Idle(Shutdown) power drain ~3 % seems about the same for me.
Status readout from OLED versions
First number is system controller. (Mine ga98e2bd this may not be the lateast release as mine may be unofficial)
Second is HID(keyboard) your is from 2025 - 01 -07 or January 7th 2025 Sorry about date format. (Mine is 20250111 as I recompiled mine for a different layout.
As for the screen black screen, if you can try to test with an external monitor. (micro HDMI to HDMI connection required) For me I had to blindly login and start sway before I could use the external monitor.
It looks like you may have done the January 7th firmware that does not play well with the revision 1 of the display. If that is the case you may need to follow these instructions.