Here is another reality check for you all.
Never expect 100% perfection. In construction, there is no 100% perfection in the building game. I can guarantee that for sure. Rather, aim for that 98% perfection.
Do you know why? Building a house, no matter how small the house is, it is still a big project that involves a lot of people throughout the process.
Yes! lots of HUMAN WORKS. I would not be surprised if there are going to be some problems or issues that might occur, but it is not about blaming who causes it, rather it is to work together to resolve the issue. Having this in mind will help to ease your mind when an issue does occur.
Please note that I am not saying that you should accept things that are not done properly. What I am trying to say here is to allow that 1% buffer of expectation that things might fall out of places.
If you have this in your mindset, you will have a much more enjoyable journey for sure.
It is a process and if you manage it well, any problems that arise will be identified early and rectified.