b. pay for the renovations so that I can earn cash flow.

@Raj G.First, to be eligible for a Solo 401k plan you must be self-employed or have a legitimate business with earned income and no full time employees (over 1,000 hours per year) except yourself and your spouse.If you wish to invest in real estate then you need self-directed Solo 401k, brokerage or major financial institutions will not help.

Alright so for actual advice I would find a tenant who can maybe do handyman work or keep the grounds clean, etc for reduced or likely free rent.  

Or does it make more sense to investment in better neighborhoods and earn lower returns?

could you reduce the reno (as in paint cabinets/update hardware and maybe skip countertops).

We are a Turnkey company when you define it as an investor can step into an investment hassle free and begin earning their return. 

To reduce the risk use a big name that has been vetted by the big banks (Zelle comes to mind, not sure about Cozy). 

You've documented your attempts- I would just open a separate account in your name and advise the student of the interest being earned, .01-.02 cents a month and be done with it.

and we are realizing that we got a great deal and we should earn about 10-15% return every year.

You insure to reduce your specific risks.