---one has been in place about 1 year; just started a new 1 year lease; seller says he is a PITA and it typically late on his rent, but pays the lease-ordered $25/day late fee-Seller said he wants to enter an owner carry / owner finance scenario, as he wants to spread out his tax liabilityHere's where I need your advice:-Seller paid $150k for both properties four years ago. 

Check out this series of articles:  Flipping and Rehabbing"Hard Money Lenders" are a typical source of funding for fix and flips. 

Typically, investment properties are valued based heavily on the income capitalization approach.

On the B to C transaction, is "C" buyer typically another investor with cash or private money?

The buyer doesn't perform you typically have to just go file an eviction just like with a tenant except when is the bond for deed filing eviction it will usually take about 45 days to complete the eviction process.I've done a few over my time both buying and selling and it's not that difficult.

The Austin area housing market didn't care that February is typically a slow month.

Baby Boomers typically live in the higher end homes.

Typically need to pay monthly or quarterly?

Typically what he provides is a letter stating the property has been sold and here are the new instructions to contact for maintenance issues and instructions for payment (also provides a copy of the deed, showing the sale). 

If you want REAL rate of return/cash on cash, look outside of the typical areas.PS, a lot of the areas that are becoming popular/gentrified and hot topics now are just as crime-ridddn as areas that are completely ignored.