I kind of jammed through it.  

Once you're deemed credit worthy by lenders you can start using leverage which needs to be used VERY carefully but is also extremely powerful.I personally do NOT recommend that someone with a trades or self employment 'life track' as you are describing is best suited to buy a first house with cash, and for instance use your time to fix it up.Few reasons here:Firstly, often the kinds of 'cash deals' available are ones that can to generalize tend to be more cash flow type properties (as opposed to equity properties). 

Use conventional financing to buy each 4-plex individually, but close them simultaneously.It is likely that the owner doesn't care what kind of financing you get, but their loan might be a tied loan, so untying them becomes more complicated. 

I would not skim coat it for the reasons listed above, and even if it wouldn't delaminate, best case scenario, it's still going to look kind of weird. 

Please advice me on which markets and what kind of properties should I be loving for.

There seems to be a lot to unwrap there and I haven't done any kind of independent research to verify if every ecomic body out there is raising their forecast of growth or not.

AS @Russell Brazil  says there will for sure be another recession that's a given.but who can time it.. and will it be regional.. there is always mini recessions and hot markets.just look at when a factory folds in some smaller burg.. or like right now look at South Carolina which is ON FIRE for jobs.Boeing 787New Volvo factory not yet manned but thousands of jobs and support coming in the next yearMercedes building a new factory same thing.building a new embarkation debarkation for cruise ships in Charleston  14 hotels under construction in Charleston.. then look at another market where not much is happening and won't be happening.but right now real estate is hot and frankly its pretty solid right now.I am not sure on the MF side that kind of goes up and down on over building .. and commercial as well.Like I probably would be a little nervous in the Mall space or some commercial with brick and motor kind of changing.But with the owner occ resi seems pretty solid.. no sub prime NO liar loans.. 

What kind of deals are you looking for?

I absolutely would love to hear more about the benefits of a SDIRA... and you driven the nail into the point that I was wondering (IRA's are good for stocks and bond investments while SDIRA's are good for investments in other vehicles, ultimately making it beneficial to have both kinds of IRA's for diversification purposes.)I will definitely reach out to you to follow-up in the near future.

If i’m Budgeting for a 550-600K property, what kind of DTI “cushion” should I leave myself?