Then I realized due to Chrome's design, when a page doesn't load and an internal error page appears, Vimium is never called. Then suddenly I've got to resort to ctrl+w and friends some of the time. After dealing this for a while it eventually became too annoying to even bother with.
Looking for alternatives, I stumbled across Pentadactyl[1]. Tried it for a few minutes and realized it was time to make the switch back to Firefox.
I've learned that in the end, for basic software like browsers, window managers & editors, consistency by far the most important attribute; Pentadactyl/Firefox really delivers on that end.
Further, in regards to the issue you describe, Pentadactyl offers the ^v command which enables pass-through mode, which sends all keys except escape to the site you're browsing.
Also FWIW, but I find Vimium convenient just for j, k, J, K, G & gg on most sites. :)
covers some (your mentioned) basic functionality. However the Opera API is not as diverse, or wasn't at time of dev, afaik.