Also, 10 year old renovations will most likely not achieve market rents, which means that any buyer will need to invest in renovating the units)Is the basement unit a "legal" basement unit?

So I have a few questions. 1) As I have never done commercial real estate, am I legally aloud to help them?

Is there a way to do this while legally protecting myself from liability (i.e. having them sign a waiver)?

I can also start my web design/ or biz marketing company.

If you can keep your cool, and let the courts and the legal system do their job, then you can do it. 

Getting answers to those questions will determine the amount of capital reserves you'll need to bring in addition to the down payment, but I'd guess at a minimum you'll need $15k, which drop your returns to the single digits until you can increase rents.I'm not 100% sure of the legality of the county's laws regarding sun setting lots, but you could reach out to the state's manufactured housing association and potentially get the two lots back if you agree to infill them with new units. 

The most seasoned property managers will have special designations like MPM, RMP

Small home repairs and late night phone calls are a minute part of land-lording, there are also a lot of legal aspects involved. - City rental certifications can be required- There is certain paperwork that you need to give someone at the time of signing a lease with them (lead based paint       disclosure and pamphlet, inventory checklist, etc...)- If someone stops paying rent you may need to go through an eviction process- When screening tenants you need to do a thorough check of who you're renting to- There are several Fair Housing laws you need to be aware of when placing a tenantOften times, a PM company will even be able to cover their own cost by receiving the highest rental amount possible for your investment, most likely higher than you could by yourself due to the exposure and avenues they have for marketing.

IF NOT PAID back in that time you would have to go through the legal process of claiming the propertyMY Question, what have you seen as the average winning % for these liens?

Luckily I have a friend who does design/build for restaurants to help at least guide me on the basic steps for the renovation so I am not flying entirely blind there.