I bought a brand new car a year ago and still have 5 years to pay it off.

If you are a buy and hold type you will find many opportunities available; perform your due diligence as many houses require more construction efforts or cosmetic improvement than others.Hope this helps.  

Personally, I take dated and time stamped photos of our work, require signed contracts and change orders for work to be performed and text or email any important information relevant to the projects completion all in an effort to document just in case.

Would it be an issue if I was self-performing a majority of the work myself?

How bad you get to screw someone has limits.To stay away from such issues, investors need to justify their actions, in valuations and in charges for services performed, justifying fair and equitable dealing.

I have been researching and growing my knowledge in various aspects of real estate for the past 8-10 months, but no cash to perform.

I am brand new to real estate investing and hope to learn a lot from this community and fellow people in the greater Seattle area.

I mean house built in 1890 with 100% drywall, including ceilings, brand new HVAC (heat pump), brand new water heater, bathrooms, etc.  

That should get the attention of someone high up to get some heads rolling.if it doesn't I would send another letter so the same higher up stating the actions you will take that will be billed back (plus any administrative surcharge) to the tenant for not performing per the lease.  

Push the money into federal municipalities, state municipalities, and paying off your most profitable property in my opinion.Federal and state municipality funds are tax free investments, and mine perform in the 8-9% range, which means tax effective 11-12% range, equal to that of a decent cap return for real estate, plus they usually pay monthly.on top of that, the last thing the states and feds wont pay is their water, power, and sewage bills, hence why its a good steady flow of income.Also, it gives you three sources of solid residual income.