Call an agent, they should be able to help you or point you to one that can help you. 

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

I want to start building relationships with the agents and visit some of them to pick their brains, figuratively, of course. 

If you provide specific services (called "substantial services", think hotel) then it’s considered a business and reported on Sch C (this is rare for an STR). 

How do agents get around this?

There are many types of licenses that will qualify here, including builder's, RE Agent/Broker and Property Manager. 

You could test it and see how it goes but I think you'll have more vacancy and might have to lower prices to keep them full.

The IRS prefers that the rental is in service for > 1 year but 2 is the rule of thumb You can defer the capital gains and depreciation recapture on sale of your townhouse provided you meet the 1031 Exchange timeline and requirements...

I found a property, contacted an  agent, made an offer.

We had over 15 offers.some at full ask and others where over ask.