That’s a great video and I’m thankful (for future dads switching) that you included the mistakes, too. Based on my experience, installing the clutch “backward” from the intended mounting got me twice, too. Even after I was aware of what I should have been doing, I still did it wrong twice.
The good news is that once it’s all together and mounted correctly, you shouldn’t have to worry about much else related to the motor. It should run for years with only minor tweaks to the valves.