Geez, that's a lot of oil production...

35% is the perfect position, unless you find food to be a limiting factor, then set it higher, but you won't make as much money as you would with 35% tax rate.

Depends on real life commitments too. Generally I think going for the 18 hour bonus is best, but sometimes one must adapt to one's real life schedule too.

Generally, does PS attacks get more land?

I concur, such prices are too high for food. I would suggest buying agri science whenever possible and constructing some farms to offset the higher prices...