(a) The obligations of the tenant and its sureties to the Indian landowners will also be enforceable by the United States, so long as the land remains in trust or restricted status;

(b) Nothing contained in this lease shall operate to delay or prevent a termination of federal trust responsibilities with respect to the land by the issuance of a fee patent or otherwise during the term of the lease; however, such termination shall not serve to abrogate the lease. The owners of the land and the lessee and his surety or sureties shall be notified of any such change in the status of the land;

(c) There must not be any unlawful conduct, creation of a nuisance, illegal activity, or negligent use or waste of the leased premises; and

(d) The tenant must comply with all applicable laws, ordinances, rules, regulations, and other legal requirements, including tribal laws and leasing policies.