Generally, you change your computer’s region from System Settings: Language and Region: Region.
If you want to overwrite this manually, follow the below steps (intermediate difficulty):
Quit Opera
From the Terminal application, paste this line followed by Enter: open -e ~/Library/Application\ Support/com.operasoftware.Opera/Local\ State
Look for and manipulate this line, "location": { "country": "us", "country_from_server": "US" }
Save, and reopen Opera
10.63 is the last version that will run in this system. Various security issues were fixed since then, but how widespread are the exploits of these issues in the web are anyone's guess, and not only security will be affected but also the compatibility and performance in many websites probably.
Thank you for the reply, sgun. This is an unfortunate omitance of such a nice feature and usability experience, IMHO. How I wish Opera would at least add a preference tick box for this feature in an update even if they'll prefer to leave this unticked as default if they deem fit.
Now for some strange reason, after I enrolled in an Adobe Online Course where I used my Gmail, the password field of my Gmail has been clear even though I had Password Manager saved my pw in the past. Sigh.
No. Of course Google knows your searches, and can track your visits on sites that use their ads - they can do that in any browser. If you leave Google as default search engine they may also know what you typed into the address bar (due to suggestions) ... other than that Opera does not report to Google.