Bruno- Snowplowing is the best way to slow down/ stop. You probably also want to get out of the tracks. If you're not going too fast, take one foot out and use it to snowplow. If you're going pretty fast, you may feel more comfortable getting out of the tracks altogether.

Wahine- Do you know the difference between V1 and V2? If not, learning to V1 may be your ticket to getting uphill (it's a lot easier). I also second the suggestion to spend time skiing without poles (it really helps sort out body position/ balance issues).

Skiierchickie- At the last clinic I went to- they were actually teaching a wider based stance. It sounded like this is new in the last year or two. They specifically advised against overlapping the ski tails. I'm still muddling through some of the other things they pointed out and haven't paid much attention to this yet. It seems like skating technique has changed every time I go to a clinic.