We are both reasonably low income and the business only net profits around 7,500 per year, so since I have dependents to claim, the self-employment tax would not negatively affect me right now, and since my mother is retirement age, that scenario seems like the best option. 

Employers, property management companies, creditors, law enforcement, could all be those with permissible use.

A) Rental- Ordinary Income rate B) Flip - Ordinary Income rate + Self-employment taxes C) Sale of investment property  ( not rental) - Capital gain rate2.

You therefore do not put the property on a Schedule C (thus saving you on Self Employment taxes). 

When contributing to a Solo 401k it is mandatory that all employee contributions cease before age 70 1/2, employer contributions may continue as long as self employment earnings continue.Comments please?

From Treas Reg §1.121-1(b)(2):...In addition to the taxpayer's use of the property, relevant factors in determining a taxpayer's principal residence, include, but are not limited to—(i) The taxpayer's place of employment;(ii) The principal place of abode of the taxpayer's family members; [Empasis Added](iii) The address listed on the taxpayer's federal and state tax returns, driver's license, automobile registration, and voter registration card;(iv) The taxpayer's mailing address for bills and correspondence;(v) The location of the taxpayer's banks; and(vi) The location of religious organizations and recreational clubs with which the taxpayer is affiliated.Always good to work with your CPA on strategies such as this. 

With my rentals and expenses for depreciation I now get a refund every year and save a ton in self-employment taxes.

You do not want them as tenants.It is utmost important to have 1 year savings to weather the storm while seeking employment.

@Mike HoranIf you are self-employed with no full-time w-2 employees, you can set up a Solo 401k & rollover funds from a non-Roth IRA as a tax-free direct rollover and then invest in real estate.

We are both employed full time.