Example if the home is listed for $ 50, I have a contract for $40...

I'm just speculating, but we've already seen strategic defaults in commercial real estate in the last 6 months or so (example: Marriott hotel in RTP to be released to lender after loan default).

Typically they have a clause in there that you have to owner occupy it or hold it for a period of time like 3-6 months.

As far as I can tell every HOA document has something like this one form or another:The term "single family residential purposes" also shall be defined as: (1) one or more persons related by blood, marriage or adoption, which may include only parents and their dependent children, siblings, parents or grandparents; or (2) by no more than two unrelated persons living together as a single housekeeping unit and their dependent children, siblings, parents or grandparents.See Article III Section 3.1 here as an example: https://1drv.ms/b/s!

Typically, they may be more willing to overlook some issues, like current transitional neighborhood, etc, they sometimes have enough cash and other non-descript income to afford a non-refundable option consideration payment, along with somewhat higher than market rent, which would hopefully cover your holding costs.

If it's owned by an LLC I'm able to look that up online and can typically get a phone number / address. 

This is typical for real estate transactions involving an SDIRA.UBIT and Debt-Financed Income: The Internal Revenue Code imposes UBIT on income derived from debt-financed property.

I keep hearing about 1031 exchanges, but I'm finding that flips typically can't qualify because I need to hold the property as an investment for two years and then my profits from selling need to be held in a 3rd party account until the purchase of a new like kind property.

If you can cross collateralize with your portfolio that typically helps with the rates, we offer HML's around 10-15% (10% on the low end if there's a lot of collateral or repeat clients and also depending on the terms of how long the loan is needed) limited to no points too.

Rent rates typically are lagging behind.