Have another 2 one-bed condo in escrow closing in December 2017. 

We just had a sewer line replaced because it collapsed.

I have little experience,  but you should be able to open a line of credit against the property. 

(Some where along these lines) So I wanted to know are any of you marketing though online sites such as these?

Is this in line with your experience?

If so, how do I document the late payments so the paperwork holds up later down the line if there are more issues?

If you are going with a wholesaler you better have your ducks lined up either cash or a hard money loan in place 

Check out line #6 ...The following fourteen items must be included in any contract between a homeowner and a registered home improvement contractor for home improvement work.

Bottom line, be sure when you analyze the properties in Auburn you are not just considering cash flow, but also the resale value (assuming depreciation) after your holding period, and expect high maintenance/ CapEx expenses to include covering the costs of heat for the tenants (as many can't afford $100+ swings in monthly expenses, so you are better off paying for it yourself and keeping the rent coming in). 

If he screws up you have all materials ready to go for the next guy in line to pick up where he left off.