I have a few hours on skis. Directional control, in my experience, is not a big issue. First, if you're not using on a runway, you can take-off and land more into the wind. Even if your "runway" is narrow, you can still point the airplane somewhat into the wind, reducing the crosswind component.
Second, all the skis I've ever seen (not many) have a steel runner down the ski centreline, that helps the ski dig in. That works very well at keeping the airplane straight.
Once you get used to the idea of having no brakes, it's not much different from wheels. Taxiing is no problem, but you have to be a bit careful going over the ridges and bumps in the snow.
Not having flown floats, I don't want to speculate on the comparison.
The primary function of the design engineer is to make things difficult for the manufacturer and impossible for the AME.