As soon as you drop skiers off on the runs you are outfitting, whether self guided or not. If you are hauling them to, say, a cabin or hut then you can legally get paid for that. The only way around the permit process is to get compensated for your "legitimate shared expenses" for the trip. In other words you can't make any money, you have to spend the same $ amount as your guests, all expenses equally shared, not including the cost of the equipment, only those supplies you all use on that one trip. Trust me, you don't want to get busted for "illegal outfitting".
If you threaten to take the USFS to court over permitting your proposed use area, and they already allow snowmobiles in that area, then the USFS may have to grant you a permit. That has happened for an outfitter on Elk Butte, near the town of Elk River, Idaho.
Then there is the problem of snowmobilers driving all over your untracked powder and you never will be able to stop them. They will follow you snowcat tracks everywhere you go. But if you want to take your friends skiing and are operating without a profit then you can do what you want, just like the snowmobilers do.
One other possibility is the 501-C3 (non-profit entity) approach.
Bottom line is if someone, anyone, doesn't like what you are doing and turns you in, and you are in any way breaking a law, in this case a CFR (federal offense) you are looking at six months incarceration and a $6k fine, answering to a federal magistrate. You only get to have two such convictions and you will never be allowed a guides license or to get a permit.
But don't give up the legal approach just because some ranger doesn't like profit.
-Pat