One of the things I'm trying to figure out is if I'm better off getting a few lower cost properties or on higher priced property. 

There are significant advantages to investing here (lower barrier to entry, much better price to rent ratio's, etc. etc.).

I’ve been searching for a form or contract I could use to recast or modify the terms of a loan that I seller financed a few years ago, with the intention of lowering the monthly payment for the borrowers and extending the repayment timeline.

Or if you want a lower monthly payment, then do the 20% down.You can also negotiate credits with the sellers to use towards your closing costs or rate buy down.

Certainly more areas with lower property taxes.

Business owners won't want to get tied up in litigation and if there is a good chance they will lose, it is easier to simply follow the contract.How would that work with a lower-end tenant? 

I would be beneficial to determine if they are other aspects of the property that make it a worthwhile investment (tax, appreciation etc). 

You can always use a software like Turbo-Tax and follow the prompts.

That's 50k a year gone and you are losing tax write-offs and equity potential.

Do you have a current need for that cash flow generated from the tax savings?