[0.97] Jubilation

As for what the real % is, my best guess/theory is that when items drop or are potential'd, there's a certain chance that they are 2-line or 3-line (I think this has been estimated to 5~10%). That's probably the same % used to change an item from 2line-->3 line. This guess is based on the fact that changing something to epic/unique is similar/a little better than finding epic/unique from a drop/potential scroll

I would assume this as well. But I'm pretty sure the 3 line chance right of the bat is 20%.