Today the new PCB design is finished. I'm quite satisfied. It's probably not my finest work and the PCB area is larger than necessary, but it's single sided with only two short leads on top layer of the board.
I haven't made and tested the board yet, and that will probably have to wait at least until next week.
For the moment, this is it, and if the board works as intended, I'll probably call this project finished and start something new.