What this makes me realize is that I need to 1. find a really good bike mechanic who is willing to experiment the bike and 2. learn all of this myself. The latter is not going to happen most likely - The cost of that for one bike would be more than paying someone to do it.

And finding a bike mechanic who has the time and knowhow is not easy. It's not cost effective for them to tinker on one bike for long and that is completely understandable. I need to find a local hobbyist I can trust!