I noticed that the land allocation "boxes" placed by zillow and redfin sometimes are blank with just pure land and no house or anything.  

The age, size and type of property will impact your costs, but as a general rule of thumb Fannie Mae recommends that a property owner should allocate two percent of the total property value annually to cover maintenance expenses.

The previous investor did a ton of work to the building and after seeing many that are available right now in other neighborhoods, my contractor said this one was done correctly and is the best so far hands down. 2-flat with possibility of creating a garden unit for even more income.Cash on Cash ROI is 16.05% with 10% allocated to property management.Cashflow: $747.45/month while overestimating all of the variable/fixed landlord expensesMy big question is: Is it worth the headache?

Investor 1 does not want me to spend more money (I had allocated 20k total) on the house to get it to FINAL status under the existing agreement. 

How did you two make that transition (aside from the financials) in terms of re-allocating your time, business needs, other ventures, etc.?

As long as the allocation of the investment side of the property you want to purchase is at least as much as the property you sold to do the 1031 then you can avoid all tax.  

Even allocating a portion of the monthly rents towards the down payment is an exposure.Each State can have unique issues with this approach, so you should ALWAYS get legal counsel on this subject and  how to draw up the agreement. 

What percentage should be allocated to taxes, overhead business expenses, put back into the next investment, payed out to business partners, etc..?

You've obfuscated the actual income and expenses, so it's tough to know if you've allocated for any vacancy, what your capex and maintenance amounts are, etc.

I really need to spend time getting a system down now...considering a VA, but just need to identify what I could allocate.