Is there a way to tell from the ShareASale affiliate stats how much has been earned for 2nd tier commissions?

I see that if someone signs up but not sure how to see if they earned any 2 tier commissions for me.

Also is there a way to see the total number of affiliates signed up under me?

You should be able to see them in your regular stats. I know for me they show up there and indicate 2 tier commission.