And if you're being proactive and shopping before you close the sale of your old property you can actually extend that 45- day window to 90 days.

Or to build a new one.The timing issue is only on the sale of the rest of the property. 

I relied on a property manager who ended up really messing me up.

When owning property with an unrelated partner, you can choose from several structures: Tenancy in Common (TIC) allows unequal ownership shares and independent transfers, while Joint Tenancy with Right of Survivorship (JTWROS) ensures the surviving owner inherits the property.

what were some things that drew you to these specific properties?

The financial of property is good:      DSCR = 1.3; LTV = 45%;Both my liquidity and net worth passes Chase's test.

Fewer but better properties.

I got a property in old Brooklyn.

I currently have 2 properties, for 5 doors, which are cash flowing about $1000 a month, after all expenses, cap ex, etc. 

This slows down your acquisition of new property, but isn't as stressful when interest rates go up or if you have vacancy.