[Sarang]

For #1, that actually could be low refrigerant, but it could be other things as well. I would say it's worth doing one of those $75 AC check ups at a reputable shop. The refrigerant level needs to be just right, not too high or too low, so it's best to have a shop check the pressures instead of trying one of those recharge it yourself kits.

It could also be other things. There's a sensor that turns off the compressor when the evap coil starts to ice over. So it could be operating correctly if that's what's happening, or it could be covered in gunk and letting it ice over, resulting in more time with the compressor off when it does detect the ice. The evaporator is deep in the dash, so I hope that's not it. The labor cost to get to it would be high.