They do have versions on the FTP site ftp://ftp.opera.com/pub/opera/android the numbers referring to the version number (that is, 3400 is 34.00) ... but you'll note they also specify ARM7 (though of course any later 32-bit ARM processor should work). If you have an older phone or one with a non-ARM processor then I don't know ...
I occasionally will have the top part of both facebook mobile and desktop disappear on my LG G pad tablet. I try to scroll up to see the top but it just refreshes. Usually a whole restart of the device solves the problem.
I've had better results on all my Androids by using 'developer options' and forcing gpu draw.
'destroying every activity' sounds like your symptom, which is to do with RAM and memory.