Focus on Cash on Cash return for Buy and Hold Strategy?

[Scott Schafebook]

I'm in my 30s, and I think about real estate as a long term way to invest savings accrued from my primary job. My current plan for a couple rentals I've picked up over the years is to have them paid off by the time I'm around 60 years old, and have it be a supplemental revenue stream in retirement. I've been lucky with my past purchases, and probably like many, while I have money to invest, I'm concerned that I may be better off holding off until 2019. Here's my questions:

1) I work with a few investor agents, and in the summaries it always distills down to CoC %. How much should I care about CoC with the strategy listed above?

2) Does market timing matter much if anything I buy is for the long term anyway? (Of course, on this question I welcome any dissenters that think there's a better approach like investing with syndicators vs going it alone)

3) My past properties have all been condos (many I've lived in for a short stint). I use PMCs for the transitions, but manage them remotely given condos have less monthly upkeep needed. I'm thinking about buying my first duplex or triplex, and potentially using a PMC that I trust in the area to handle the day to day. For buy and hold, which is the better route (condo + self managing remote, or duplex/triplex + PMC manged)?

4) I've been most focused on the Seattle market, but haven't bought there since 2015. Is this still a good area for long term investment?

Thanks!