Motor is an AO Smith UQS 1202R rated at 2 hp, 230 V . It has two capacitors, assuming run and start.

One is rated 35MFD 370V (run Cap) other is 63-77 MFD 270 V (inside end cap)
If by centrifugal switch you mean the V shaped spring mounted unit at the end of the main shaft in the end cap that then yes. It closes when pump is turned on right.

had the pump head off and replaced seals yesterday. spins freely by itself , more resistance when pump backing plate / impeller is installed but still easy enough to turn by hand. Bearings sounded /felt fine.

When I removed end cap to check wiring one lead was discolored (as if it got hot) and plastic sleeves of the disconnect terminals was hard / and cracked off when I removed terminal. Re soldered one terminal that looked a little questionable. End cap area was clean , no obvious cat hair,dust ,grime or earwigs .Both Capacitors look Ok not swollen etc.

On another note last time i was running on high I had to get it to run from switching to lo first the flip to high. If I try to start in high it hums and doesn;t run. When i did get it running in high (lo/ high trick) it ran fine then made some strange noises, not worn bearing noises but more like it wasn;t getting enough juice then was fine then would do it again.

If switch to lo it just runs fine.

Thats about all I can can add.

Not true . It was working fine for a long time then slowly and more regularly it would trip when on high. More recently it has got wore and worse and now will probably only run 5 minutes or so (depending on ambient Temp also)