A few examples that have been surfacing regularly across many states- Crazy late night parties from STR tenants... the landlord is liable and can be fined or worse, depending on the location and severity.

If you don't like the contractors your getting than I would suggest becoming more active on Biggerpockets and connecting with @Darren Sager and others doing regular BP Meetups in your area.

He also asks me to send the check in mail and then he will send the lien waiver in mail after the amount is cleared in the bank. what is the regular practice to get lien waivers from the GC's? 

He had a regular full-time day job with medical insurance.

Also check to see if fees have been more or less regularly increased over the past 10 years, or if they have been essentially unchanged.

By time you figure in the added expenses of mid term rental and potential vacancy/turnover a regular rental at slightly lower rate could also work out the same. 

Account Closed points out, many folks are holding onto their regular W2 jobs.

@Alex Wise, also because of the increased inventory in most markets due to"regular" homebuyers no longer in the market to buy, higher interest rates can be off set by motivated sellers accepting below listing prices, paying for closing costs, and paying for points to provide the buyer a loser rate.

Should BORROWER default in the prompt payment of sums due LENDER, LENDER may immediately proceed against GUARANTOR, and shall give written notice to the GUARANTOR, together with an accounting of all sums due as to which BORROWER is in default, by regular or certified mail.

I don't know what a regular SFH sells for in that market (I just know the COMPS you said about other townhomes) but if you can buy lots of homes for under $100k I would think that people that can't qualify for a traditional mortgage may not have the 3.5% for the down.