Dunno about the Demon Kit.
Waxing is pretty personal, and depends on the condition. Icy, man-made snow, more often 1-3 days. Powder 5-10 days. If you're going straight 6 days, I think 1 wax before you go is fine, wax it afterwards, unless the snow condition is horrible and icy, throw in a wax if you really have the time, but I would just do it after.
Tuning, tune when it gets dull, also condition dependant. Frequent riding, tune it once a month. Take out nicks and stuff if you run into rocks, etc, quick sharpen.
Some people say kits have all the extra stuff you might not be using, it is maybe cheaper if you buy items that you think you would be using. But if you just want to buy everything in one go, and the kit is easy available for you, just get it (comes in a nice bag with everything in it).
The thing is kits may not have professional precision tools for beveling or real sharpening; so from what I read, you would still want to consider taking it to a shop to do a tune up once a season.