But what percentage of their students actually are successful, I don't know. 

It's an equity sharing group where you receive a percentage of your equity in cash up front with no monthly payments.  

The courses / mentors rely on the success of a small percentage to show their programs work but you have to ask would they have been able to do it on their own for a fraction of what the program cost.I did not see a cost associated with the Flipstress program after doing a Google search - 95% of what came up was from the Flipstress program itself which would have me question how big it is and effective the program is on a wide scale.Before sending any money I would see if you can find anyone that has used the program and find out what it did for them. 

It showed that maintenance/cap ex is higher than all the calculators default percentage would reflect and higher than I would have expected.  2/2 Condos with just interior is ~$300/month.  

I would like to pay a percentage of the sales profit.

I'm ready to buy but according to Financial Times, markets are predicting 1 full percentage drop in rates this year.

Our LLC bought it 5 years ago, and could be convinced to sell off a percentage.

What average percentage are ADU's in this area increasing the SFH property values in the St.

A percentage of every builds profit upon selling?

I'd suggest digging into the exact dollar amounts on a monthly and annual basis rather that measuring by rate percentages.