50LB limit, then afterwards you will get dinged.
some airlines suck balls with fees. And yes, you could get nailed with extra boards, or boots, or outwear thrown in. Depends on the carrier and how bad they like to fuck you in the ass.
As for the boot thing, you don't need a boot bag per say, but if you pack other stuff, depending on the carrier, you can get nailed.
2 pairs of skis= 2 boards.
I put everything in a big bag, I throw my bindings on top ( not attached). Some airlines are clueless, and I get all my outwear, and crap in too.
make sure it is under 50LBS, and I imagine you are fine.