Do codes P2104, P2127,P2122 & frequent ABS&ESC lights on have any relation to my car needing hydraulic system @ $2,000?

What is a "hydraulic system"? Those P codes you listed are related to accelerator pedal and throttle position. My question to you: What are the "C" codes? Those are what set the ABS and ESC lights. Then, what is being done for troubleshooting? Your diagnostic "gadget" is not painting a full picture. The dealership GDS tool is likely more descriptive and surely comprehensive. That coupled with technician experience and shop manual reference is probably creating a valid diagnosis regardless of those "P" codes. Certainly, get a second opinion before dropping $2,000.