Command-A to select all your Firefox Bookmarks Export to HTML desktop file(Maybe make a folder)
In Opera
Go to Settings > Import and export
File > Import and export.
Choose the file name, change the location if you want to find it easily, and click "Save".
Import the data file according to the instructions of your other browser.
When you go to the Torrenting page to attempt log-in, where in the process does the error appear? (When you access the page or when you attempt to send the log-in?) It sounds from the error description you quoted that setting up a log-in to that site may involve the site server sending you a special client log-in certificate to be used thereafter. However, it appears that either Opera isn't accessing the old cert correctly, a correct cert no longer exists, or there's something wrong in the handshaking process with the server to negotiate the cert and perform verification. Have you tried setting up another account at the site (to obtain a new client cert)?
I think the issue is that many people were using the old speed dial. Opera has been saying it was going to go away for many releases now and the only way to keep it was by enabling it in flags or being grandfathered in. When they finally did remove it the transfer to the new speed dial was jarring because it didn't save the speed dials for some reason. If you've been using the 'new' speed dial for the last several releases already, because its been the default for awhile, nothing changed.
Mask as Internet Explorer. You can set the preference only for the google site if you like. (right click, Edit Site Preferences, network, Mask as Internet Explorer)