This year, I finally made the leap and purchased a duplex and a SFH, all rented, all cash flowing beautifully, but have a question in regards to business structure and setup. 

-AlexYou’ll be able to qualify for the tax deduction and the Like-Kind Exchange based on how you structure the deal, but yes to both possibilities  

Is this is a size thing (company just needs to get bigger/have more equity), or perhaps a business structure issue, or should I be looking at different financing sources other than local banks?

 Congrats on finding a deal and being able to structure seller financing.

Grayson County is really a 2 year school, but also gearing up to supply whatever the employers like TI and Global Wafer need. 

We've found it has superior reporting features, integration features, and is overall more efficient to work within than other REI-specific software.The downside is QBO is not set up for REI so you'll need to do that or work with an expert to ensure it is set up for your business appropriately.Something else to keep in mind is your entity structure and how your entities file tax returns.

But, nearing retirement and then, will be looking more at the type of vehicle  you supply. 

Also means no regular heat source.We always leave the cabin with a good wood supply in the winter, fire starters, lighters and such to ensure they will have a heat source.  

Remember your costs will be more for an STR, you'll be paying for a lot of things you wouldn't with an LTR - higher STR insurance, all utilities including internet, supplies like toilet paper, paper towels, dishwasher detergent etc, upkeep on furniture and linens if damaged, yard maintenance and grass cutting/snow removal, trash removal, etc.  

Buying 25% below FMV is tough in a market that has 5 times more demand than supply.