I'd like to see some examples of how words may be freely invented.
Well, there is a verb "kamerować" (incorrect, low register) which was freely
invented (derived from the noun "kamera") by someone who didn't know
the proper verb "filmować".
Kids are usually good at inventing new words :), but if you were looking
for something like "Dave - to Dave" then I've never heard anything like
that in Polish. It would have to be something like Michał - michałować,
Dawid - dawidować, Bożena - bożenować and it'd sound quite ridiculous
in Polish.