Don't be afraid to ask personal questions - this is more than a rental application-Will a percentage of their rent go toward "principal" every month?

You could also do a lot of the work for them for a percentage of the profits.

So a large percentage of these really cheap MH with land are cash sales.

Not sure if that changes the management percentage fee.

1: What percentage of the revenue do you put into the company coffers for future purchases vs what you pay yourself for income? 

They might  just charge a percentage, see if you can find one with a flat fee - You will definitely want to do a title search / get title insurance to verify what liens have been put against the property.

Looking at the rent roll (to see what percentage of current occupants move in this past April/May) as well as at historical occupancy (for any trends in seasonality of occupancy) should shed plenty of light on the situation so that you can make a good decision.Mike

For a deal like this, with long term tenants and no maintenance issues, would it still make sense to put 10% capX away or would you want to drop that percentage some since the house is in good shape?

This, in turn, increases the cashflow.Rent increase percentages ALWAYS lag purchase prices.  

Some lender's may lend a certain percentage of the purchase price even after the renovations have been made.Some lenders will lend based on the appraised value at the time of the refinance.