Self employed

1) No.  Your employer does not have access to anything other than the W2 form they send you in January

2) It depends on the state that you file for unemployment in

3) Yes.  It is possible, and not uncommon, to have more than one W2 and/or 1099 form to include on your tax return each year

4) The earning son a 1099-K will need to be included on your tax return, and may impact the amount of taxes due.
5) You shouldn't receive anything other than the 1099-K from OnlyFans.

6) You would include allowed business expenses on your tax return.

7) I am not sure which Schedules you would need to file.  That information will not be on the 1099-K.  TurboTax can walk you thru the process.

😎 OnlyFans may ask for a W9 so they can be sure that the 1099-K has the correct information on it when they send it to you.