may, at the request of the Indian tribe or tribal organization, delegate to the Indian tribe or tribal organization such powers of supervision and control over Service employees as the Secretary determines to be necessary to carry out the purposes of this section;

shall provide that expenses (including salaries) relating to services that are shared between the Service and the tribal health program be allocated proportionately between the Service and the Indian tribe or tribal organization; and

may authorize the Indian tribe or tribal organization to construct, renovate, or expand a long-term care or other similar facility (including the construction of a facility attached to a Service facility).