With MCC, there's no interior temp sensors at all regulating AC temp, compressor cycling so the compressor cycles on/off due to AC freon pressure (hi and low pressure switches). If your AC cycles more often than you think is normal, and they do normally cycle btw, start by having the system evacuated by a shop with a good recovery machine as they measure the weight of freon removed from the system. By doing that, the technician then knows how its weight compares to the systems full charge weight (1.65lbs in your car). If it was low, it should be fully recharged with AC dye added so that the next time it becomes low again (not before), it can be visually inspected for evidence of leaking dye by using a blacklight.

Leaving your heater core hooked up as it was designed shouldn't be adding un-necessary heat to your interior and although you can bypass it, I wouldn't do it with my own car UNLESS the heater core was leaking and I didn't need heat.