well, qu is not something you find in Greek words. It doesn't bring to mind anything in Latin. (Perhaps it's related to the Catalan cognate of Spanish querer 'to want, desire' which is from Latin quaro, quaerare, 'to look for, search' whence English question.) The form auto is from Greek for 'he; self', and erastia, no doubt has something to do with 'love' in the sexual sense. (Cf. εραστης erastēs 'lover' and ερωμενος erōmenos 'beloved' are the two sides of a Greek homosexual relationship.)

The etymology of Latin masturbor is not agreed upon, but I've never seen one linking it to urbs 'city'. The ma part is usually related to manus 'hand' and the sturb to sturpum 'immorality; disgrace; rape' or an s-form of turbo 'to whirl, twirl'.

Ceci n'est pas un seing.