Lifelink does for their Dynafit skis. But not many people ski Dynafit skis, so that doesn't do much good. The letter opener works fine good to trim - as does an ordinary razor blade.
I've a different pair of skins for most of the quiver. I usually buy my skis slightly used, so 2 of the last 4 have come with skins already. Their's enough difference in width & length interchange is more pain than it's worht. The ones that didn't come with skins were mostly longer, skinnier skis, which are fairly easy to find cheap skins (just don't get the Black (Mohair?) Ascensions from REI)