Is it possible to charge the customer the "Just 2.9% + 30¢ per transaction" fees? I want to assess dues for a association, but have the customer pay those fees. i.e dues are $100, so the customer pays $102.90+$0.30=$103.20
It isn't something you can automate in Wave. You could set your price higher in accordance to that, but it's unlikely that Wave will create a feature to pass these fees along. This is because passing on these fees to your clients isn't legal in every country, or even in every region.
You're welcome to adjust your prices to compensate for these fees, but I strongly recommend making sure that it's legal to do so in your area first.