I would double check the zoning and such and get it in writing with city/county.

Turns out they were not familiar with writing business policies vs. residential policies.I am using IRA Financial Group and they have been very helpful in getting this ball rolling and after double checking with the tax attorney, they agreed with my interpretation of the code regarding this situation.And yes, I have been researching this in depth and am aware of the usage restrictions. 

Are simultaneous, back to back, or double closing allowed in Missouri, or do I need to do an assignment closing?

How would I go about double closings in these areas?  

Doubles in 46222 not so much.  

I do all of my closings with them, whether double close or assignment of contract.

We have wholesaled 3 properties so far and all have been large profits so we chose to double close on all 3. 

Let listing agent double-end. ~ $140/sq ft.3) May 2014. 4plex in East Oakland - $385K + $45K Rehab - on-market property (over 200 days).

If you are doing a double close you could face 2 sets of closings as you will have closing cost on your buy side from the seller and your sale side with your new buyer.  

A $200k property doesn't rent for double what a $100K property does.