I just downloaded Opera and really like it. I work with forms and do not want the addresses saved. his is what I found out
Go to Settings.
Click Advanced in the left sidebar, and click Privacy & security.
Scroll down to where it says Autofill, then addresses. Turn the button off. Worked for me!
That is the perfect solution IF you don't want Opera to autofill forms.
However Opera actually has about the best autofill of the common browsers. The only problem that I have with Opera's autofill is its ridiculous habit of frequently asking if I want it to save an address when it has just autofilled a form using the address that was already saved. It doesn't do this every time, but it does it often enough to be annoying.