Would anyone know if Snaza is shortened or a correct Polish name?
Snaza is correct; it’s formed from a root word ‘snaga’ meaning cleanliness. Other variations are Snazyk and Snażyk but those are formed from snażyć (to clean oneself or to try your best or extra hard).
Miotke is patronymic from an old Slavic name Miecislaw, today Mieczysław.
Wirkus is formed from a German word ‘wirkhus’ meaning tool shed.
All of those are from Pomorze region of Poland.
Lewandowski ; I guess no explanation needed, you’ll find people with this name all over todays Poland.