We have quite a bit of experience in this, and we have found (at least in our experience) that doing the larger single listing always nets more money and less headache (i.e. guest of one unit pissing off guests of another). 

Also, keep in mind that you'd need to stay up to speed on all proper documents and forms in your state as well as maintaining a status with your local Association of Realtors, pay for MLS access, pay for lock-box access, attach to a brokerage and onboard with them, along with several other items.

For ex) I told all my "tenants" they could only have overnight guests 2x a week and that the place was for one person only...so if they had a partner that they couldn't live w/o I suggested they get an apartment w/ that person.4.

Do you want to receive a call at 11:00 am when the guest loses the remote control?  

Don't get into any of the details and expressing anger over the matter via text message, just ask for a brief conference call when they are both available to discuss the status of the closing, and possible next steps. 

I'm thinking almost all brokers will make you join if you have active license and want to actively assist buyers and sellers.One option might be if you only want to refer out business to other agents, some brokers might have what they call "referral only" status.   

Right now it seems rentals are the way to go (like investing in gold vs startups) while the market settles.

One great system we have implemented into our STR management company is the use of what we call "concierges" or people that will go and check the property after each and every reservation with a "Walk through" or a checklist of all the things that should be ready for the property to be ready for the incoming guest.

Should I jump into this world digging for the gold, or selling the shovel to the diggers?

Occupancy Requirements for Deployed Active Duty Servicemembers Single or married servicemembers, while deployed from their permanent duty station, are considered to be in a temporary duty status and able to meet the occupancy requirement.