Were you in contact with other real estate investors beforehand and worked out arrangements to workout a double close?

Can a tenants in common agreement include an arrangement that would allow me to buy "shares" of ownership over time?

It protects them and allows you to keep your holding costs down a little.I've never done it, but I've arranged financing for it a couple times and had the deal fall through (knock on wood).Beset of luck!

A deal was struck up soon after the initial contact, but the time difference added more time to getting the contracts arranged properly, sending and receiving, to the final signature.

Or should I wait and have my own agent arrange to see the property (it's also a friend so they're going to help be an extra set of eyes on the investment also).

When you talk to the tenant, inform them that you will be the new owner soon and since they are on a month to month tenant arrangement, that you will need them to vacate.

Would you be OK with that arrangement?"

The two tenants are responsible for working out their living arrangements on their own. 

To sell without an agent, you'd of course have to  be around for showings, negotiate with the buyer (or buyer's agent), negotiate with the title company and arrange inspectors/appraisers.  

Airbnb has responded to my request that they cannot intervene as this is an "offline arrangement" and they are an online company.