I think for many people a 24x48x12-14ft tall would be a good size. Mine is 16ft tall and that gets a bit sketchy for us older folks.
My primary issue is I don’t see the profit in growing figs for fruit. You will need a heated greenhouse to avoid winter freeze injury. Heating to avoid critical temperatures will increase your harvest season.
Even clouds reduces fruit quality. They swell up and burst or just don’t taste as good. Fig fruit is too perisable to get my interest.
You might not have spider mite issues if it’s open, roll up sides, in summer. But organic isn’t as easy as it might seem. Other issues will arise with regards to fruit IME.
If you are serious I’ll discuss more. There’s a lot involved with the goals/climate/design equation.
Chilling and cooling depend on your climate and your goals. I’ve done both in a mild sunny climate. I can get 2000 chill hrs in winter where temperatures average 60/30F in winter. Summer is 90/65.
I use evaporative cooling, wet wall and large exhaust fans, for both. Throw in some shade where needed. But chilling in particular is all about designing the right setup for your climate.
Greenhouses are designed around your crop, objectives with that crop, and climate.