3) When it gets dicey, I shift back on the bike, unloading the front--just the opposite of what you ordinarily do on a roadie. This lets the front float and wander a bit, finding its own path. Otherwise it tends to follow ruts, or if the ice or hardpack is loose on the street, it will plow it along on the street. Plus, if the bike breaks through hardpack, it always causes a sideshift. It's easier to recover from the rear sideshifting rather than the front.
Interesting. So you keep weight to the back.
So what happens when you hit something you can't go through?
I'm usually back there, sort of ready to have feet hitting the ground. Usually that means a forward slide off the saddle.(We've had some heavy snow lately and a lot of remnants around. Lucky to do 5-6 miles in an hour and even then it's quite a workout.)