Also, I'm not in Iowa but as a matter of comparison, I typically use 15% for land allocation in MA so I can depreciate more of the purchase price.

A strategy you may want to consider is to allocate some of your $ and target a specific area and contact the owners using snail mail (direct mail). 

If after the flips we pull $40k out and reinvest the remaining profits with our original capital, do we get to choose which member to allocate the $40k income to avoid self employment tax on my remaining cap, or would it split and I pay self employment tax for both social security and Medicare and my spouse only pays the Medicare tax?  

Properties that use a RUBS allocation formula to distribute water costs had a reduction of 6 to 27 percent in water usage.

You'll want to start with form 8829 to get this right (and remove whatever you've entered for Schedule A for TurboTax).  8829 will help you allocate the amount between personal and rental.

Clearly your asset allocation is locked up in assets that provide no returns.

In my opinion, it is just not the most efficient way to allocate your resources. 

How much should I allocate to land?

When making the offer HUD will allocate up to 3% of the sales price toward title insurance expenses so long as you stipulate that in the offer.

Wouldn't this fall into the bucket of "VHCOL investors allocating capital to a cheaper market"?