Your post mentions correctly that only the last year or so, Opera thinks it's funny to crash and destroy all the tabs, sometimes even the bookmarks. Importing the bookmarks when this happens also fails.
Can you Not do that? Go back to what you had 2 years ago. It didn't crash 75 times per second and mysteriously lose all your data. I think the MS Word team took this over. They love to crash after you wrote 20 pages and lose all your information.