We're actually recovering well from our former financial situation, and I cleared $100K in commercial deal commissions last year to pay down 50% of our balances.

If they decide to leave you will have vacancy, turnover cost and maybe Realtor commissions.

In my opinion you will need someone who is going to get in the trenches with you, role play conversations with you so you are ready to talk with sellers and handle their objections about your commission price, why their house isn’t a worth $20,000 More than the same model down street, and why they choose a new young agent like you and I vs a more experience agent that has sold 100s of homes in their career. 

In a college town, check,first good thing.Worth about $20k, then need to do a short sale - work with the seller if they are amenable and allow you to talk to bank on his behalf, tell the bank the condition, send photos and comps and a contractor bid then include your offer of $20kGet title insurance and make sure no other liensThey do not want to take it back and go through, evictions, holding costs, title, escrow, commission etcor wait till it goes to foreclosure and back to bene [bank] and offer directly to the bank, see above.

I'd have some other fees to the "team," but they'd basically handle all the sales, marketing, and conveyancing.I heard from someone that I could take 0% commission and thus wouldn't have to pay anything to KW...but I'd still have to pay for sales/marketing/conveyancing.

Generally MFH brokers will be trying to get both sides of the commission (dual representation).This depends on your own personal acquisition criteria. 

At this point I would be ready to sell for slightly above the 570k you paid in 2016, and hope that’s enough to cover the agent commission.

HOA fee - If HOA fees are not paid, business will incur fines, so it is necessary to make the profit in the business.8) Marketing expense and advertising9) Cleaning and maintenance10)Commission (Expenses like commission, abstract fees, recording fees to obtain your mortgage are not deductible but rather capitalized )11) Insurance12)Legal and other professional fees(Tax preparation for business, not personal part)13)Management fee if applicable14) Points- you generally cannot deduct the full amount the first year but have to deduct them over the term of the loan.15) Repairs (Note always do repairs rather than improvements to rental because repairs are deductible right away and do not have to depreciate over few years as done for improvements.

I've always worked full time to support my family so a commission only job scared me.    

Factor in taxes and commission when selling it and costs associated with buying a new property.On paper STR look like they are cash cows, but there is a lot of work that goes into them and expenses/time maintaining them.