Take a ski pole
The old skiing traditions in Finland involved only one ski pole. Evolved from the walking sticks snowshoers used, one single pole was used for balance and to test the surface.
The pole did not have a wristloop at the top, nor a basket (the round piece) at the bottom. As a matter of fact, many skiers in Finland had poles ending in a spear's head instead. When a male skier used two poles, one was for balance while the other would be used as a spear or bow for hunting.
Hunting on skis
Yes, it was quite possible for the Finns to continue moving while using weapons. The animals they hunted while on skis were moose, elk, and other medium to large animals that are too fast to catch up with on foot.
Skis in different lengths?
Until 150 years ago, skiing was just a way to travel more safely across snow, with less exertion. (The loose straps on old bindings show that the first skis were cross-country/nordic skis.) In those days, the skis were stiff and could go downhill on a slope, but were certainly not meant for alpine skiing as we know it. Sami/Finnish skiers mostly traveled across snowy plains and tundra, like Lapland.
The skis also were worn in different lengths. For 1800 years in Scandinavia, it was common to use a short ski on the left foot and a longer one on the right. Covered in seal skin, the shorter ski (or "kick ski") was used for pushing. Equally sized skis did not become common until the mid-1800s.
Although the length of the long ski varied by region from 2.5 to over 3 meters, the long ski was always approximately 5 cm thick and 12-13 cm wide. It was carved from a somewhat plank-shaped piece of wood, often pine. Its bottom was grooved lengthwise and the tip was curved upward in a slightly lesser degree than today's skis.
Warfare on skis
Skiing became a crucial part of the uprising organized by Gustav Vasa (future King of Sweden) for Sweden's liberation. In 1539, fighting was carried out by Finnish soldiers wearing skis. And after 1750, soldiers in Norway and Sweden also used skis.
By the way, the oldest ski museum in the world is found underneath the Holmenkollen ski jump in Norway. The ski museum there shows visitors 4000 years of skiing history - including skis from the vikings and those that belonged to the Royal Family of Norway!