Just to be clear you are saying the stopping of amitriptyline or these other drugs causes sensitisation? Not effects whilst on it.Generally speaking, yes 5HT2C inverse agonists cause super-sensitization because of the constitutive suppression.
Amitriptyline is an inverse agonist. As such is causes sensitization.
It is suppression of 5HT2C that increases appetite. Increased activity (by itself) suppresses appetite. See Lorcaserin.
Inositol does much more than just downregulate 5HT2A.
Could you explain what you mean about inositol? I thought it sensitised 5ht2a?
I don't understand how it works at all but made everything unimaginably worse for me.