A few quick comments.
There is much bashing of DV and discounting of the Canyons. Both areas rock. DV in particular seems to bear the brunt of some sort of reverse snobism. Most resorts in the U.S. would be lucky to have any one of DV's terrain, snow, grooming, or service. The mountain is relatively uncrowded. Know the right north facing slopes and you can get fresh powder in the trees two days after people are whining here and on TGR about other areas being skied out. And DV limits ticket sales - so on one of the busiest weekends of the year, you could probably do worse than to hit the DV ticket office early... And, just to be fair - Canyons is massive and has a huge variety of terrain as well. One nice thing about both areas is that they have a great mix of groomers and off piste - which makes them good for dabbling in powder and still being able to back it off easily if you want to.
Powder. I think most people get selective amnesia about their first times in powder. They just think about how much it's like flying. They forget about the times they dug their tips in and went head over heels, floundered around, spent an hour+ working up a sweat looking for that damn ski... If you happen to get lucky and get dumped on while you are there, give it a go. But don't be surprised if you have to look at your first time out as an investment in learning. Just do it with a smile! Someday you will be happy you did. This is another place where the right gear and someone to show you the ropes will make your life much easier. And where keeping your ego in check can make for a laughing fun time instead of a frustrating one.
I have not yet made it to Alta. However, several friends who know the area well keep saying pretty much the same thing - that to get the most out of Alta, you need to hike it. And hiking it with someone who knows the place well supposedly makes life much more fun.
Oh, and one other thing - you clearly are not allocating enough time for this trip