My opinion? Keep your oil changed, run it 'til winter and then take it down - if you decide you need to. Flatheads are tough. If you have any compression it'll run.
Use some Marvel Mystery Oil in the gas and crankcase to loosen up the valves.
If your radiator is clean and the block is clean your heating problem should disappear when timing is correct.

I doubt you'll hurt the crank if you run as-is until winter. By then you'll know what you need to do and have some practical road experience with it.