He may visit any doctor or facility he wishes with this insurance. However, for a list of doctors/facilities in the Visitors Secure PPO, follow this link: VisitorSecure PPO
If you select coverage for International Including USA, the insurance should cover for all of the locations you listed. This includes coverage as soon as your brother-in-law leaves his home country (ie: travel) as long as you have included his travel dates in span of purchase.
Travel medical insurance covers for any new, unexpected sicknesses or injuries. Unfortunately, it does not cover for anything related to a pre-existing condition. It is up to the doctors discretion whether or not he declares a condition as pre-existing. For more information, see: Pre-Existing Conditions Explained
Insurance rates are regulated by law. You can't find the same insurance plan for a lower price anywhere else