Not a fast strategy, but in the expensive Bay Area, it works.During the years I lived in this home, my husband and I simultaneously invested OOS in Seattle where he traveled for business. 

One acronym I always liked is that real estate is said to be the IDEAL investment:Income (from cash flow)Depreciation (tax deduction due to depreciation)Equity growth (via principal paydown by tenant)Appreciation (generally, over time, even though I assume 0% appreciation in my return calculations)Leverage (and the corresponding inflation-profiting benefits through long-term fixed interest rate debt)@Keith Weinhold of Get Rich Education does a great job of explaining the many simultaneous profit centers real estate provides.  

The refinance event and a change in how you hold title (going from C corp to personal names) can be done simultaneously.

When You do a lease option/sanwich lease you simultaneously "buy and flip" you sell your option and let your subtenant exercise it directly from owner, right?

The crisis will catch everyone by surprise as it unfolds, but afterwards, everyone will look back and see the obvious signs that led up to it (Nassim Taleb's book The Black Swan).I don't know how to prepare simultaneously for both possible extremes.

I'm in escrow on two properties simultaneously now, with the same lender.

Also If I try to tackle both simultaneously, what is 1.) a promising capital amount to begin with & 2.) the most ideal system to use for beginners? 

This ideally would land somewhere around 18+% for a "Good Deal".If your monthly rent is less than 1% of the property value and the value keeps going up, your long term cost will go up IF the rent does not simultaneously go up with the property value because you're going to get more taxes, pay more interest (assuming you don't sell, you're living off borrowed money instead of just ending your obligation and responsibilities, if you have to borrow mortgage for another positive cash flow property then that's different), and put more into repairs.Your rowhouse will need to be liquidated by that logic, the duplexes may need to be split, I think you should have the one you want more. 

There is a "parking arrangement" where an Exchange Accommodation Titleholder (part of the Qualified Intermediary operation) will acquire and hold or "park" legal title to either the replacement property or relinquished property, and there is a concurrent/simultaneous 1031 Exchange. 

@Cole Druffel I work simultaneously in multiple markets and have to say that by far the most important thing is building a solid team of people that you can trust.