Possibly moving to Denver from Victoria Canada, please help sell me on the move

Some of the answers to your questions will depend on where in the Denver metro area you are located.  I find that SE Denver has a very different vibe than Boulder county where I live now.  Both are great but I'm very very very partial to the Louisville/Boulder/Lafayette area.  Many of my closest friends are also my training buddies and I don't know anyone who isn't very active.  It's just part of life around here.  Even on my rest days I start to feel guilty because I simply can't go anywhere without seeing someone either running or cycling.  Great hiking nearby.  And if you want to get into other sports there's kayaking, climbing, skiing, snowboarding, mountain biking, cyclocross (Boulder's new Valmont Bike Park opens next month!) and the list can go on.  Races are plentiful including triathlon, running, cycling, urban races and more. 

We have some great restaurants, farmers' markets, museums etc.  I hear there's great nightlife but with a very early work day and training I don't do a whole lot of late night stuff. 

A good friend of mine is from Victoria and from our frequent conversations I'd have to say Colorado is pretty similar all and all.

Like others have said, the city and metro area covers a lot of area and everything from the weather to people can be totally different from a few miles away so it really depends on what part of town you will be in. The upside is that there is probably a part of town that will fit your needs and have what you want and like that isn't too far away from everything else.