A/C

The mechanic should have connected the AC manifold gauge set to determine this. Visual inspection of the sight glass isn't the best indicator. If it "looks" good, then this should be blowing cold. Something else is amiss.

Few places are good w/ automotive AC systems. Even fewer are competent to work on the Prius AC systems which is very different from a conventional car.

Consider a roadtrip/weekend excursion to SanFran (Luscious Garage) or Berkeley (Art's Automotive), to see a good Prius competent shop. Their labor rates are less than the dealer, but will likely be more than your local mechanic or a national chain repair shop. You will get what you pay for.

NO.

Cruise control not working properly is likely a broken clock spring and/or brake light switch. You need to rule out clock spring cable and brake light switch.
Brake light switch.
Depress the brake pedal, the brake lights come on? Release the brake pedal, the brake lights go off? If yes to these two questions, your brake light switch is not the cause of the cruise control not working.

Clock Spring Cable.
Do the radio and AC steering wheel buttons work at all positions? A simple test is to park the car with the wheels pointing forward, and the steering wheel dead centered. Make the car IG-ON or READY (see owners manual if you don't know what this means). Place a piece of tape at the very top of the steering wheel (this is your 12 o'clock position). Test all the steering wheel buttons (radio, AC, cruise control, etc), at this 12 o'clock position. Do all the steering wheel button functions work? Move the steering wheel to 1 o'clock, and perform the steering wheel button test again. Go to 2 o'clock and test the buttons. Keep doing this at the other "hour" positions (3, 4, 5, 6), then go to 11, 10, 9, 8, 7, 6. A broken clock spring cable will reveal itself by intermittent operability of some or all the steering wheel buttons, at certain hour positions.

This post has some good pictures of the clockspring cable and why a broken clock spring causes problems.
2006 Prius clock spring (spiral cable) repair | PriusChat

If the brake light switch and clock spring cable are working, it will be something else. But these two items are the most common culprits.

Some people prefer to buy counterfeit clock springs off crapBay (eBay). These same people also report the part failing SOON (~1year). If you have to pay for labor, you will have wasted money.

Most importantly, the clock spring connects your steering wheel airbag to the SRS/Airbag ECUs. Read post #3, and decide for yourself, if your life is worth $10 (counterfeit) or $220 (Genuine OEM). Be careful of counterfeit Clocksprings / Spiral Cables sold online | PriusChat

Learn how to check the 12V battery yourself.
Is my inverter coolant pump slowly failing? | PriusChat

Read Post #5 (how to apply a load for a more meaningful measurement of 12V battery health)
Read Post #8 (Battery SOC (State of Charge) chart and 12V AGM compatible smart chargers to consider buying).​