I nervous about an interest only HELOC, the rate sounds like its variable and not fixed. 

There are all sorts of variables, but it comes down to you not BSing yourself and if wholesaling leave some margin for your buyers.  

Do i guarantee a percentage increase in value... do i exchange it for profit sharing in the business or perhaps just ask for a higher yearly rent to make up for it?

I used two variables: 1) will this action garner more rent, better tenants or faster time off market; 2) will this action cause less needs, repairs and concerns while it is rented.Not sure my example fits your request.

I'm familiar with Building Management Systems (BMS) and Variable Air Volume (VAV) dampers that moderate the air volume in each space with multi-speed (actually VFD) motors for the blowers and dampers that are solenoid controlled, but the systems I'm familiar with are way too expensive for the average home.

Evidently a percentage of the payment went on alcohol.

There are challenges in Trenton as in other urban areas with a struggling economy and large percentage of non-working people.

We collected a monthly rent plus a percentage of overage.

The problem with this is that, if the stock market (value of your account) drops to the point where is to below the margin percentage limits, then you will have a margin call and have to immediately fork over a ton of cash to cover it.

BTW, from what I have seen of personal guarantees, you as guarantor will be liable for the full debt amount - not just your pro rata portion based on ownership percentage.