Thanks for the link, but it didn't offer anything I hadn't found in my own searches. Since posting yesterday, I did however discover that Opera did indeed import my Safari bookmarks, but, it did not populate the same way that Chrome and Safari bookmarks populated. When I imported Chrome an Safari, the "Favorites" bar content populated with respective "Favorites" bar content, and other bookmarks populated in the sidebar in "Other Bookmarks." Safari content populated in the "Imported Bookmarks" bar which wasn't opened because the other browsers' content populated in "Other Bookmarks."
So, now the problem is I've literally THOUSANDS of bookmarked pages and hundreds of repeat imported folders. Apparently Opera doesn't provide for a mass-deletion of bookmarks. The only way to do it is ONE AT A TIME! It will not allow "Command A" to select all. Not impressed at all. This will be a huge time-sucker, one I'll not deal with. Bye-Bye Opera.