I was thinking that maybe I could live in it and maintain it for me and a partner, but I would need a partner to put up over half the cash.

In California you can charge up to one and a half times the months rent for a security deposit.

I spoke to a woman yesterday that I talked to a week and a half ago.  

In most cases this can be around half of the cash flow!

Or, for roughly the same price I could buy two of those units completely and profit $775 a month (that's factoring in the expenses too) and hold full equity...I think your CBFT numbers are a little rosy, but let's say they are half of that (387.50/mnth), that is $4650/yr ... a 3.8% return.  

The metrics need to fit your objectives and market.I understand your reasoning for looking for rent at 3% GOI, but be advised that in many areas it will not be a reality; in our local market you have to hunt hard for half that (1.5%).  

Dont purchase in half empty complexes.

Having to repair a roof for $5k, which is not unreasonable, will cut your interest income to maturity in over half.  

I'll be meeting with the park owner in half an hour to discuss how this situation would work.

Ask the realtor for the past 2-3 years of operational finances  ... s/he will either try to intimidate you away from wanting/needing them - in which case, walk away - or will provide you with a set of rosy, half-fabricated numbers {accept these with scepticism ... if you get in the territory of a deal, you will ask for corroborating information from his/her accountant or tax returns}.Once you have the financial data, take a run at analysing it, then bring it here for folks to review and assist you with coaxing the {likely} truth from the numbers.