Solar has an energy credit and Starlink is deductible as business expense. 

If the property were owner-occupied, would I only receive credit for one rental unit's income, while the non-conforming basement income wouldn't count?

I appreciate the reminder as well that if the gain is fairly low then it may make more sense to just pay the capital gains taxes now versus 1031 exchange. 

You have to put 5% down vs 3.5% down, rates are usually higher, but if you have strong credit, your PMI cost can be cheaper than that of FHA loans. 

Honestly, I think you're estimated expenses are a bit low.

You should be able to go as low as 10-15% down payment with your experience.Ground up Financing: Most "ground up" financing options require a bit of experience - 3-5 exists (rehabbed & sold or rehabbed & refinanced in the last 3 years).

And maybe diversify a little, invest half in a low cost S&P500 fund like VOO and the split the rest across 2 or 3 syndications.

If my target would be low income residents, are there any grants, tax credits, or funds available to help me with the conversion? 

When loans were called, was it due to specific triggers like delinquencies, insurance lapses, or low-interest rate portfolio loans held by smaller banks?

You've done a great job with keeping your debt low so I have no concerns about your level of discipline to use/reuse a line of credit.All the best!