>How bad is to have an application with lots of forms with private sessions?

It's not bad. To me it's more manageable than default because you don't have to worry about relationships, filters, etc. of outside forms. Our hospital system has hundreds of forms - modeless and modals, and it's running smoothly.

>I am having some trouble with my application and I am getting sick debbuging it so I thought I could just leave the forms I have problems with, with the Datasession set to Private and debbug them with more time. (I have a deadline and basically that's the problem).

I think you need to be more specific on the problems you're encountering. UT can't help you in anyway without telling here what kind of problems you are encountering in your programs.