Number 2 has merit. Here are a few more.

1. Most thermostats do require calibration, and nobody has time for that. This has a similar effect to your second point. Proper air flow (or lack thereof) throughout the home is also important.

2. Sunlight makes a huge difference. A temperature that feels comfortable at night may not feel comfortable at noon in a home with a lot of natural light. Same as a sunny vs a cloudy day, indoors or outdoors.

3. Men and women have drastically different tolerances for comfortable room temperature. In general, non-menopausal women tend to appreciate a slightly warmer room than men. This plays out in office spaces all over the world, with many women running space heaters under their desks.

4. Clothing obviously makes a huge difference. Some people prefer to dress for their desired temperature; others prefer to dress for their physical comfort and let the HVAC balance things out accordingly.

5. Medical conditions and medications and diet can all drastically affect one's body heat output. For example, anything that boosts serotonin is likely to make one run hot. Stimulants will constrict blood vessels and make one cold, especially in the extremities. And we all know what alcohol does (dilates blood vessels, allowing more heat to escape the body, lowering one's body temperature despite actually making them feel warmer). Blood sugar levels make a difference. The list is endless.

But it's interesting that most of your thought process went into how HVAC systems and humidity work, versus the simple fact that the people themselves are just drastically different (see points 3 through 5).