Yes, having the tabbar on the left is amazing in Opera, esp. with a 16:9 display. I've uploaded a screenshot for you[1] to show you my current tab list. They're grouped into tasks I'm working on atm. On the left the groups are expanded, on the right minimized.
CTRL+# are reserved for websites stored in SpeedDial. But maybe [2] helps you. I doubt that any experienced Opera user would require such a feature, because the more fluent you become with the UI the more often you swap tabs around. Instead I stored sites into the SpeedDial that I visit regularly, e.g. CTRL+7 is HN :)
[1] http://i.imgur.com/Z55rPDh.png [2] http://my.opera.com/Tamil/blog/go-to-a-specific-tab-using-ke...
Ctrl + 1,2,3... let's switch between tabs. Do you know the equivalent? I'm going to try using it for a while if you say you can run that much tabs and it still runs smoothly. I usually have 40+ tabs open at all times.