runegang What can custom forms assigned to a organization or user be used for?
Well I didn't even know that you could attach a form to a Organization or User (never tried). But if you want ed to have additional information on a Organization or a User you could create a form and add it to the them. That form would be able to hold additional information.
Say you were a Custom Sneaker Outlet store, and you had other Organizations (companies) that bulk bought from you and you wanted to assign the Org a Account Number from your POS or Sales Database You could make a form and attach it to the Org and then populate that field.
Continuing to use the Custom Sneaker Outlet store, say your end customer (Users) also used the same support system, and you wanted to track their Account number from your POS or Sales Database AND their show sizes. You could make form and add it to the User and then populate that information.
These examples fall apart at this point, since I would negligent if I didn't point out that you can probably do this easier by adding the fields directly to the built in forms Organization and Contact Information. I think that the feature (manage forms) on these two objects exists in case you want to add custom forms to Orgs or Users that already exist. Since users that already exist wouldn't have forms that didn't exist when they were created.
runegang Is it possible to make a form in a ticket only visible to one organization or user?
Sadly, the answer right now is no. I am hopeful that this is a feature that will included in the forthcoming 2.0 release.