As you rented the unit accepting a discount due to the roof issue and landlord has been fulfilling their obligation by lowering your rent, you have no basis to complain. If you go to your local housing authority and complain, they will likely declare the unit uninhabitable. You can freely move. Expect the landlord to sue you for all damages to the inside of the property and for lost rents until the property is repaired and rented again, since you created the damage by puncturing the tarp. In your situation, I would keep my mouth shut and move at the end of my lease, hoping I don't get dinged for the repairs inside.