Is there an extra charge on top of Stripes merchant fees for doing it through JotForm?

2. Is there an extra charge on top of Stripes merchant fees for doing it through JotForm?

There is no charge for payment transactions here in JotForm and we do not get any percentage of each payment submissions.

I checked your account and it is under the free account. Keep in mind that there's a limit of 10 payment submissions per month under the Free plan. If you are expecting more than 10 payments per month, I recommend you to upgrade your account. Here's a guide: https://www.jotform.com/help/331-How-to-Upgrade-My-Account

I hope that helps.