Absolutely, it is possible to ski in mtn boots like the Scarpa Inverno. If you are a confident, solid skier and put some practice time into using them, they are quite skiable and can even be fun. However, I would not go out on them if skiing was the goal. It isn't always "fun", but you get the benefits of skis. They are great for approaches to winter climbs, like the sisters, broken top, etc.
I have a set of silvretta 500's mounted on some light, short (165cm) skis. This seems to work well, as the Invernos' soft plastic and zero support make turning a little more challenging. If you get in the back seat on this setup you WILL be going down.
I would absolutely not recommend this as your first and only ski setup, unless you also like being beaten with a frozen haddock and having snowballs shoved down your pants.
You haven't skied until you ski invernos with a heavy pack in breakable crust w/crevasses below!