If you are going on your own, I would save up and then one deal is done move that money to the next deal and so on.

They get to save money on living expenses and we have a much higher yield then LTR's by far. 

Eliminate debt, establish a budget, and save.

I am retired now.

The fact that they don't have critical thinking skills and limited income/saving, makes them desperate and easy target.

You could ask that they put a year or so of savings into a separate account on which you have view access or receive a monthly statement so you can see they have the ability to pay future rent.They aren't going to last without other income or savings with income at 1.25x rent.

A good real estate accountant can save you thousands of dollars by leveraging entity selection and formation, tax deductions, cost segregations, bonus depreciation and tax planning.I recommend finding an accountant who specializes in real estate taxation, business taxation, financial planning and tax planning.You may want to consider working with your accountant remotely to expand your options.I would also recommend looking for a accountant willing to work with you throughout the year.

Live in one unit and rent out the others to cover your mortgage.Seller Financing: Negotiate terms with the property seller where they act as the lender, often requiring a smaller down payment and bypassing traditional underwriting.Partnerships or Joint Ventures: Partner with an investor who provides the capital in exchange for a share of the property’s equity or income.Lease Options: Use a rent-to-own agreement, which allows you to control the property while saving for a formal purchase.BRRRR Method (Buy, Rehab, Rent, Refinance, Repeat): Acquire a distressed property with short-term financing, rehab it to increase value, rent it out, and refinance to recoup your initial investment.Pro TipStay in close communication with your lender as you approach your next purchase.

I hope you are asking two separate unrelated questions, because there's no point in doing cost segregation for properties held inside your self-directed solo 401k, save for some very rare exceptions.Some of the Bigger Pockets experts who operate reputable costs segregation companies are @Bernard Reisz, @Yonah Weiss and @Julio GonzalezSome of the Bigger Pockets experts who offer Solo 401k administrator services are @Dmitriy Fomichenko, again @Bernard Reisz and @Brian EastmanReach out to them and see if they can help.

I asked the question once on BP if anyone ever got saved by their LLC and the post had I think 60+ comments, but no real good textbook story to support the case for protection through entities.