ski weight: within reason, the wrong place to save weight. you need ski that performs well, with minimal compromise. the ski is what will keep you alive in the descent. Most top skndreasiers that ski extreme terrain (Andreas Fransson, Chris Davenport, Jon Morisson, etc) ski on Salomon, kastle and Blizzard skis, and not the lightest models.
perhaps you feel that at your skill level an the terrain you will ski, you don't need high performance skis? Let me assure you that almost any slope can be terrifying under the wrong conditions.
somewhat similar to choosing an ice axe: would you climb ice with a sub-pound ice axe?
binding: this is the place to save weight, and Dynafit is the only binding that is worth considering. with Fritschis, marker, whatever, you lift the binding at every step. With Dynafit, you only lift the boot. This makes a difference of a pound or so, which gets lifted about six inches per step, much more impact than the same weight in a ski, which stays on the snow when skining. And Dynafits ski well, certainly better than Fritschis.
i would save weight on poles, BD cf alpin an excellent choice. can save a pound of weght, which you lift at every step.
ski width: if you are an expert skier, you can get away with sub 100mm waisted skis. But why? most likely, you will encounter shitty snow conditions on every tour, and you can waste lot more energy sescending on a skinny ski than on the up. And if you look at the best skiers, they all are on wider skis.
boots: Definitely get a stiff enough boot that will handle skiing on ice, with Dynafit fittings, even if you don't get the Dynafit bindings now. I use BD Factors, since I don't want to compromise, but I hear the Virus light is a good boot. And don't listen to people that will tell you that you can ski ice on a soft boot. You can, if it is consistent, and you know it's there. The problem is that sometimes ice is burried under a thi layer of snow, and you can go from powder to ice in a fraction of a second. Which is why you need a stiff, responsive boot.
You have so many opportunities to save weight, from clothes, pack, gloves, water (don't carry more than a liter, and keep adding snow as you drink- there you just saved 2.5 pounds!!), that you don't have to compromise your safety and the pleasure of skiing.
I'm sure I will get a lot of nit-picking replies, but i have done a lot of this, and talked to a lot of people that do it at a very high level, and I learned the hard way too.