Hi Toplica,
If I understand you question correctly, here's what I would do...
I would make the userID and preferences (your examples) attributes in your ActionForm super class. That way, every ActionForm class is extended has those values. I haven't entirely thought this through or tested it, but it seems in theory like it should work. You may have to reset these values every time you change ActionForms, but as long as they are children of the same super class...