Yeahh, took some time, but my CPU and with it the Computer is working. After playing some pong I'd now like to ask a question to the materials presentation SLIDE 41. This was the diagram I had on my screen for days now, but I did not find out what the numbers at the in- and outputs of the ALU represent. I also didn't find the solution in Shimon Schocken's explanation video.
D register to ALU 11...01
Mux16 to ALU 10...10
ALU to outM 01...11
Do those finally only represent the transfer of any fetched/computed binary?
I think they are just trying to emphasize that those lines contain the data that they are focusing on for that slide. It appears that they talk about the sequence of processing a C-type instruction over several slides.