The basic element hiding rules listed here - https://adblockplus.org/filters#elemhide_basic seem to work. With the exception of tags. If a tag such as div is specified then the rule stops working.
I have converted my custom filters to remove all tags.
There is virtually no documentation about this anywhere. Not even in the release notes! It would be great if a manual for the general syntax is specified online somewhere for advanced users. Users who are unaware might just port their ABP custom filters, hoping that they would work. An online conversion facility to transform filters in other syntax to Opera syntax would also be useful.
One surefire method to stop automatic updates is to remove execute permissions from Opera's opera_autoupdate executable. This prevents Opera from ever checking for updates. Run this command in a Terminal window.
when you press synchronisation button on the right, type your credentials and then select 'Choose what to synchronise' link. There will be 'Bookmarks' on the checklist visible on 'Advanced Synchronisation Settings' window.
and tell me what email you put there (it does not have to be your email, just some email address that let me find you in out Crashlog Analysis Tool) that would be very helpful.