I suggest checking their acceptable use policy, and TOS.
My guess is they don’t police whats being sold with their software since its really none of their business.
WooCommerce doesn’t process payments so you’ll still need to use something like Authorize.net or another payment gateway.
I think you can host the forums yourself free of charge.
However I’m not sure, my install of it is missing half the features that are talked about in the release, so maybe you do.
And if thats the case, then so be it, but it’d be nice if it was stated a little more clear.