I like the idea of using pro rata share among tenants based on unit size.

Do you know if the trust has a non-pro-rata distribution clause? 

It’s typically done on a Pro-rata share  based on the amount of equity invested. 

Thus, a non-member MLS fee is justified if it is are higher than that paid by members by an amount which is approximately equal to the pro rata amount of association dues devoted to the MLS.

They are taking on risk by signing on the debt, but are they guaranteeing their pro rata share of the debt?

That would get split up pro-rata amongst the investors that made that 50% contribution.That's a simple example--it can get much more complicated than that if you wish, or if that's what it takes to get the money partners interested.For example, there could be a preferred return, which means that the money investors (yourself included because you ride side-by-side with the others on the money) get 100% of the profits until achieving a specific return, such as 8% or 10%. 

CA has a LLC tax of 800 per year unless your equity exceeds 250,000 then the tax goes up pro-rata.

I have a proctor account and pay for insurance monthly.. also Zurick has the same type of add and delete monthly function... pro rata the rate is higher than a yearly premium.. so you save money if you can sell at 6 to 8 months... and in many of mine were we are 30 to 90 days we save a ton.

The Landlord then passes on a series of expenses related to the operation and maintenance of the building to each of the tenants on a pro-rata basis.

So you are saying that the amount is the same every year (except for the pro rata amount the first year if bought mid-year) and that the cost basis is the same every year assuming that no improvements are made to the structure?