I plan to host a foreign student at home. It is through a private route, not through school. The parent of the student will pay me directly for room & board.

1) Is the income taxable?
2) Do I have to depreciate the house? (I prefer not to)
3) Is there any expense not deductible on the contrary to what people normally think?

1) No, because that is reimbursement for costs incurred by hosting the student.

2) No, not for renting a single room within a home.

3) This is essentially a tax-free transaction. You claim no income for the reimbursement and no deductions for the costs incurred.