Hmmm China is so diverse and confused in and of itself it's difficult to make generalizations.
Hong Kong and Tibet aren't really on the same level. Very few in HK have any REAL inclination to not be part of Mainland China. Of course some people wish the Brits were back (India struggles with the same problem of identity), but what's on people's minds is not really sovereignty.
In addition to the issue of money from taxes on Ecigs and why they are banned in HK, Hong Kong's Health Ministry is extremely vigilant whether or not they can back things up with sound evidence. It's just a byproduct of what's struck HK in the last decade. We've had to deal with avian influenza several times as well as SARS.
One of the moves to combat epidemics for example was to make it illegal to spit or throw cigarettes away on the ground. This happened after I left Hong Kong and every time I go back it see how much cleaner the city is because of it.
Hong Kong's government doesn't fully understand the
ecig and takes preventive measures. They'd rather err on the side of caution. If ecigs end up being completely safe and beneficial and TAXABLE, there's no reason for HK to be
ecig friendly again.
They've just dealt with too many crises to not be overly cautious.