Led Goose,
To answer some other parts of your question....
Yes, the rolling view as you fly over many countries in a single flight is pretty cool, as is watching another airliner fly past. Some of the sunrises and sunsets are very 'picture-skew'.
I've flown with many guys who are very active in GA outside of the airlines. There doesn't seem to be too many issues with it. Unfortunately it's pretty limited in Hong Kong!!
Regarding outside work, Cathay couldn't care if you commute from a Romanian gypsy village, and run a fleet of trucks used to transport dancing bears in your spare time............as long as you are at despatch when you are supposed to be, and your activities don't cost them any money.
lmh