How much should we allocate to demo such a structure and prepare it for development so that it's attractive to developers?

Experience is key for sure - but there is also the reality of LPs needing to allocate capital and the number of experienced operators available to invest with will likely be smaller than the LPs who want to invest.  

I do not have a very urgent need to sell, simply I want to allocate the money to some other assets.

This exchange would function in the name of the Partnership and said partnership would acquire separate replacement property that would be allocated after purchase to each of the owners individually.

Not allocating cap ex and maintenance because an item is not expected to fail soon is simply providing a misleading return estimate.  10% maintenance/cap ex ($132) is less than half of reality and maybe less than 1/3 of reality.  

I'm thinking if you create a simple journal entry to allocate the amount of interest paid, principal paydown and any lender required escrow, that this would help that limitation.

Charge rent based on market rates and allocate based on square footage or amenities.

Don't always look at what the bank account balance is, look at the books to see how much was allocated in the reserve.3-6 months reserves are usually for regular maintenance or not full-on big ticket items. 

Disclosure: I am a heavily allocated real estate investor, and SMB owner (which I acquired) 

All cash flow is allocated to a Capex HYSA for maintenance, repairs and updates.