The property value must be a minimum of $250,000 USD, and the credit score requirement is at least 700 points, among other conditions.

Value your money more. 

Generally speaking, Boston proper is an appreciation market (low cap rates) unless you have a solid value-add play.

I wasn’t looking to add value or find something off-market because the time and effort just didn’t seem worth it compared to focusing on my career.

There are other options, the $60,350 mortgage does exist, but you didn't say what the value of the property is, but the variable rate mortgage of 8.75% to 11.75% indicates several thing. 

I would like to maximize value.

My tax professional is stating that I would need an appraisal to show the lot/structure are valued at $400k if I try to claim $200k as a donation.

To me the value in diversification is that it helps nudge you to look for other opportunities and revenue streams where you might otherwise just be content to stay in your lane and then you'd never find anything new. 

Tons of value in learning property maintenance and tenant management.

Most lenders I work with would lend you 70%-75% of the value of the property, but only so much that your NOI/profit is 20%-25% of the monthly loan payment.