the tech that gives no maintain and repair health is too powerful.
No, the tech (Living Ships) is fine. You can achieve practically the same repair capability by having a few (2-3) Nanite Projection Arrays (fleet support modules) in your fleet. And ship maintenance cost is not really relevant anyway.
Defenses are what really is OP. Create attack ships that have 30 or more in all 3 defenses and then see if the AI can even make a dent in them. It can't.
Tourism is way too powerful. Too much money. crash system
This is indeed the case. First they give tourism a well-deserved nerf with Retribution, then they bring it back stronger than ever before by changing the racial trait to +1% / +2%. I don't understand Stardock's reasoning here.