Shopper and apparent alcoholic + skiing hard all day?
Sounds like my life before junior.
You are dealing with two pretty different entities when you're talking Keystone & Copper. Neither is what I would consider a shopping mecca, although Keystone does have an outlet of Gorsuch, where you can empty your wallet just by looking at all of the lovely cashmere and ridiculous Bogner suits. Copper has the requisite retail outlets, along with a newish store called something like, I believe, The Fall Line, full of all sorts of great ski/tele/snowshoe/flyfish clothing by companies like Arc'teryx, Kjus, DNA, etc. At Copper you're just over the pass from Vail, so if you want to *really* shop (whether that means "just looking" or running up those credit card bills), you're a bit closer to the real thing, IMO.
I don't really know the nightlife at Keystone, as it's been years since I stayed the night. It used to be very family-oriented, though, so it was apres, then hot tub, then bed.
As for Copper, there's the requisite apres venue or two, and then a couple fun options for later in the Main Village at Copper. McGillyCuddys is the local's Coors Light, pub-type hangout, and it's usually pretty noisy and busy. Pravda is a vodka bar that gets kinda clubby late on weekends, and there's also a newish place across from Pravda called The Storm King Lounge that I really like. It's got an OK wine list and things like specialty martinis and scotches. They have poker tables and pool tables and big comfy chairs and couches for a lounge vibe. Also have a DJ booth and are building a sushi bar. For a real club experience, best I have found is 8150, over the hill in Vail, where they sometimes get some pretty big acts and DJs. (Which means I feel very old
there, these days.)
River Run area in Keystone is a nice development. Where I would stay if I were there. Would vote for the main Village at Copper at Copper, just because there is more going on and some nice rental options.
Personally I have always liked skiing Copper better, although admittedly I haven't skied Keystone much in last few years. Less (annoying) yellow-jacket-speed patrol (who don't know the difference between out-of-control beginner and expert carving moderately fast), and less chokepoints. Good terrain in Resolution & Copper Bowls.