Health care Expenses deducation Question?

I pay for my own health/dental Insurance premium (after tax dollars).  It is NOT from market place so I don't get 1095A (not sure if that will be a variable. I assume these expenses can be added to health care/medical expenses? I don't have any other health insurance.

 

Health care/medical expenses are subject to 7.5% rule. Is there any phase out or even income limit?

 

Q1. 7.5% of which income? AGI? which line on 1040?

 

Q2. Lets say my AGI for 2021 is $1000000 (just as example, I don't make that much even in my dreams!) so my medical expense has to over $75000 to be eligible to deduct?

 

Q3. Lets say my medical expenses (made up number just as example) are $80000 and I can only deduct as itemized deduction $5000 ($80k - $75k)?

 

Q4. Then overall all itemized deductions has to over standard deduction to make used these medical expenses deduction?