Liquor laws in Canada are enacted on a provincial level. The minimum age for alcohol consumption in British Columbia [1] is 19.
Like the rest of North America, driving in Vancouver [2] and Victoria [3] under the influence of alcohol or drugs is a criminal offence. Those convicted of driving with a blood alcohol concentration above 0.08 face big fines and an automatic one-year license suspension. Second convictions (even if the first was out of province) lead to a three-year suspension. Note that in British Columbia drivers below the limit can be charged with impaired driving. It is also illegal to have open alcohol in a vehicle or in public places.
Smoking is banned in virtually all public places across Canada. Most provinces have enacted province-wide bans on smoking in public places (including British Columbia, where a blanket law went into effect in 2001), which includes all restaurants and bars.
Gratuities are not usually added to the bill. In restaurants and bars, around 15 percent of the total amount is expected. But you should tip according to how good (or bad) the service was, as low as 10 percent or up to and over 20 percent for exceptional service. The exception to this rule is groups of eight or more, when it is standard for restaurants to add 15 to 20 percent as a gratuity. Tips are sometimes added to tour packages, so check this in advance, but you can also tip guides on stand-alone tours. Tips are also given to bar tenders, taxi drivers, bellmen, and hairdressers.
Links:
[1] http://www.moon.com/destinations/british-columbia
[2] http://www.moon.com/destinations/vancouver-victoria/vancouver
[3] http://www.moon.com/destinations/vancouver-victoria/vancouver-island/victoria