Assuming that's true, I would recommend looking for a replacement property (or properties - you can purchase multiple in the exchange) with value of at least $725K (selling price).  

I'd recommend attending investor meet ups.

I am seeking recommendations for an app that can integrate with multiple platforms.

What strategies do you recommend for securing hard money loans for spec builds?

BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

Any recommendations on lawyers to talk to that can assist in advising on an LLC fund (if needed) and how? 

Anyone have a direct mail or postcard service they recommend for such a scenario?

Separately from all of that - I recommend reviewing your lease up procedures to improve verification of signing tenants and their agreement and aware of terms and conditions. 

Nathan above gave some good software recommendations, any of which would probably work well.

Additionally, not all transaction types support Locations, meaning you'll have to create journal entries to correct them—requiring a solid understanding of debits and credits, which can be time-consuming and error-prone.Instead, I recommend biting the bullet and upgrading to QuickBooks Online Plus for each entity.