You haven't got a clue dude.
I watched a couple of your vidoes and I have some comments and questions.

You obviously haven't been into a proper bike workshop.
The amount of pullers. presses and special tools is 100 times what you have.
The park tool stand should always be set up before use, even says so in the instructions.
A hobby lathe with a 3 jaw chuck is simply not the best in the business you claim.
When was the last time you aligned the ways on that by the way and what tolerances do you believe you can achieve?
A CNC machine does make up for tool wear, If you cannot figure this out then you better go do some research.
Professional bearing presses use an ACME thread, not some weird thing, it is used for a very specific reason that you obviously have no idea why. Your home made one is crap and you don't know why.
What is the sample size used for the brand frame tolerances graphs you show?
Thin walled tubing can be accurately CNC machined, you just need to know how, and then you go on that you machine your BB's from one side when it is obvious you will have huge runouts on the unsupported end.
The taper on the Scott BB shell is by design and within spec and if fitted correctly with a standard Shimano BB would have functioned just fine. These is a proven reliable interface.

That is just a rant from 2 videos, god help how long this post would be if I watched more or specifically took notice of the bullshit.