The 2001 5 speed automatic in your car is not the best one Volvo ever sourced. The first thing to do is to change the fluid (not a power flush-- either do it ~3.5 quarts at a time by pulling the drain plug, or disconnect the return hose at the radiator and pump it out and refill until it comes out clean). Make sure you use JWS 3309 spec fluid (Volvo branded, Mobil, or Toyota Type IV) Then take it to the dealer to have the software updated. The updated software pulses the solenoids in a very different manner from the original programming, and also deletes a harmful stop-neutral program.

My 2000 V70 has the same transmission-- the fluid change and software update made a huge difference in shift quality. I am also planning on replacing my B4 Servo cover ($24 at the dealer-- helps with rough 2-3 and 3-4 shifts). Resetting the adaptations and running a drive cycle is a good idea.

The dealer will also run OBD II diagnostics as part of the service, which may give you additional insight into the health of the transmission. Don't give up on the tranny based on what the dealer says until you've refreshed the fluid and updated the software. Others have reported success with swapping the entire valve body for an updated rebuild. Worst case is a guaranteed unit from Erie Vovo.

The cruise control may be related to the electronic throttle module-- that's one of the other shortcomings of the 2000-3 model years. The dealer can do a sweep test to see if the potentiometers are toast inside. Aftermarket rebuilders are available from $250-500 for the ETM.

Good luck!