@Sebastian E.
@Andy O'Neal
While the general STR concept is not in my "toolkit", it's clear that you and others who have responded to this thread have pretty solid ideas. I've enjoyed the thread. Thank you.
In the context that I have no real familiarity with the concept and I'm using only general business principles in these suggestions it seems to me that:
1) Sebastian's concern, while legitimate, can probably be dealt with by way of options to renew within the lease (perhaps extending out 5 years or so); and,
2) Andy's comment about extra security deposits between him and the owner being limited by law (though I'm not advocating that you should provide higher deposits than you are suggesting) may be worked around via a lease that, while similar to regular residential leases in wording, is designated as a commercial lease (a business-to-business lease) which it surely is anyway. THERE MAY BE REASONS UNRELATED TO SECURITY DEPOSITS WHY THIS MAY BE A BAD IDEA but, depending upon how Maryland (and local) laws impact STR you may be able to choose which lease type you prefer; i.e., which laws you want to fall under (of course, if a dispute ends up in court the courts will have the ultimate say in what kind of lease you've actually created).