There is a group of a dozen of my regular STR tenants coming here in a week. 

The requirement that you not personally guarantee any loans taken by your IRA/401k is a corollary of this rule.UBIT/UBTI/UDFI: Traditional IRAs/401(k)s are tax-deferred and Roth IRAs/401(k)s provide tax-free earnings - with regard to "regular" income tax.

The deal with the non-performing note is to purchase at a substancial discount and try to get it performing again so that you either have a performing note that pays regularly or sell it in a few years as a re-performing note(lots more than a non-performing).

@Grant Anderson No bank will give a regular conforming loan to an LLC.

If your regular depreciation is already more than covering your cash flow, you will likely see little to zero benefit.

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.

Not sure if my experience is going to help much, but I just became a Broker in New York and started my own Brokerage, Work Hard Realty, LLC.Prior, I was never a Salesperson and attained my Broker License from qualifying with my experience over 20 years as a Real Estate Investor.I have a lot of experience in REI and hold 7 multi-family Investment Properties in Brooklyn, NY that I buy with Partners.Prior to becoming a Broker, a few friends of my Partners, Family Members and others have been asking me to help them buy properties as they realized how successful I have become.The properties that I bought and sold made me realize that I left some money on the table.