TRT is supposed to be used year round, for life. I don't know why a doctor would take a hypogonadal person off other than for some other medical condition that warrants no use of T.
No. A diet and training regimen enhances health and quality of life, but it does not directly make T more effective.
I don't know why you would want to increase dose so long as your T value is mid-to-high normal and you are feeling good. Going supranormal does not lead to normal functioning and health.
200 mg is usually not necessary. 100 mg per week is fine for most men and gets them into the 500-1000 range. Good docs don't start with 200 mg.
Did you even see what your T value is with 100 mg?