One of the powerful features of function is that there's technically no row limits for using a function (we automatically delete rows after they're completed to make room)! Tables calling functions will have normal row limits based on your plan.
2.
Action credits will work normally within functions - so each step within a function that normally cost action credits (see here) will consume credits per row. The function column itself however does not cost any credits (action or data)!
Hi Lena! Luda from Clay team here. The product team here is currently scoping this potential feature for a future release, would it be possible for us to ask you a few quick questions? Would love to understand your use case a bit more!