Hello @ChrisR
From the last photo, some soldering seems to be making connections between pins on the IC1 but could be an illusion due to the whites soldering residue.
Have you check there is no direct connection between IC1 pin 9, 10
as for the pins 19 and 20.
And same on the USB port soldering …
Try to use a brush (like an old toothbrush) to remove the white residue or gently scratch between the soldering with like one of your multimeter tips, to make sure there is no possible connection.
Edit 1 : The more i look the diagram the more i think im wrong in the next sentence :
Yes for me (but electronic beginner here), you should have the USB connection even if the SMD ICs aren’t properly soldered except maybe a short-cut.
Edit 2 : IC2 and IC3 , the best will be to re-do the soldering (no solder adding, just minimal re-heating the surface PCB and the pins for a better solder repartition …)
For the SMD ICs, you could try to control the soldering with your multimeter (continuity check from the suspected pins to the control point / side bridge point ) but not easy if you don’t have sharp tips and if there is no control point …).
Other soldering seems good to me. I don’t see component inversion. (But not a well trained eye here)
Hoping this helps and that someone could add another point of view.
Have a good day.