I am renting a house from a charitable foundation - all of my rent goes to charity, so is that tax deductable?

No, you are receiving a product/service for your money, so you get no tax deduction. If you were paying more for your rent than the fair market value, then you would be able to deduct the extra. In this case that would be very hard to prove, since rent can be whatever someone is willing to pay, and you would only be setting yourself up for an audit.