I'm not a big fan of #5 in the winter. Realistcly, I'm a layerer, and I find that shells do NOT layer as well as fleece, as they don't breathe as well in really cold conditions. I layer up with wool and fleece - it simply breathes better, and I find I'm lighter because I'm not taking as much "extra".

I don't take a VBL. I wish I could deal with them, I can't. I instead take a decent down bag inside a rectangular synthetic, which keeps me from frosting up.

I also at least where I am, do fine without a double wall tent, but I'm typically not in snow load, just intense cold.
I light weight wood stove in the tent does help, and will ensure that your bag doesn't hold condensation because you can warm up in the morning. My shangri-la 3 with homemade stove and pipe weighs about 5.5 pounds total, and it's use in the winter is really growing on my after a few trips out with it.

I most disagree with #3. Nothing sucks more than trying to feed a bloody twig stove and find enough dry twigs under snow to melt when you need to. Forget it. Take a good white gas stove. You should be able to talk someone out of a whisperlite for next to nothing because everyone seems to have such a hate on for them. If you are in a situation to burn wood outside in the winter YOU DON'T NEED A STOVE! just build a fire!