@Sean DillonAt 18, you're in a prime position to start building wealth with low expenses and plenty of time to scale.

Maybe with a low (70% or less) LTV or an ARM and stellar credit...also depends on what type of loan you're looking for (nonQM or conventional Fannie/Freddie)

The mold house would only be a good investment if you can buy it at a low enough price to cover the necessary renovations.

It's going to be challenging to find another house hack with as low of a monthly payment as you currently have, given the low interest rate.

At this time I manage and renovate majority of all my units to keep cost low but most likely not the best use of my time although I'm skilled at it.

Is it possible to buy a property in Seattle low enough to get 1%, yes.

Once you've identified what's important and what ratios to look for to evaluate a property, all future deals should be weighted against those "good" ratios/numbers - and periodically adjust to suit your goals.

Low cost, possibly yes, but also possibly very time consuming and that has a cost.  

Short term (12 months), low loan to value with borrowers who have strong credit and significant assets.

I suggest finding one of them to do it for youMost DSCR loans through brokers have $150,000 floor with some going to as low as $100,000.