Hey! Yes you can email invoices to your users (finally!) We heard that feature request so many times. :)
Re: multicurrency subs -- we thought about this quite a bit. At the moment you'd need to create a plan per currency, with our reasoning being that you'd want to control the FX rates on your own (and setting a price internationally is a very intentional decision.) That said, how can we make this easier? This launch is a start of our investment in this space, really interested in feature requests.
Would be great if the "Pay in Full" button on the invoices used the same color that is set under Business Settings > Customer Emails > Customize Design.
Also do you have multi currency subscriptions? Or do i need to create a pro_monthly_euro, expert_yearly_dollar subscription ?