I mean it’s a fun exercise if you were looking for something to do - but 99% of your figures are straight guess work.
any estimation of revenue from gate sales requires at least some knowledge of what the sales mix of attendees are (ie day pass, annual pass, some other holiday pass). On an off peak Tuesday you may find 80% of your visitors are annual pass holders, so there is no direct gate income in that day from a large portion of your crowd.
then the avg duration of stay for annual pass holders - something not able to be tracked, as that then impacts revenue per head on F&B (annual pass holders more like to leave before lunch, or arrive after) and merch (annual pass holders less likely to buy on any given day).
There is a myriad financial lines to consider; of which you have only handled a few.
but as I said, if it was just an activity in fun, then it’s accuracy is of little consequence