Modify Wordpress/Woocommerce plugin - tagging, payments

I have the Wordpress Dokan plugin installed, I need the following done: 1. merge Paypal + Stripe payments to be used. Right now, if Stripe is installed, it overtakes PayPal and you are forced to use Stripe. If both are enabled, allow one or other to be used. 2. Product listing page - modify it so users can submit their own tags, rather than being forced to use ones created by admin. I also have Woocommerce Vendors plugin if you need source code to take from there. 3. Currently all users are charged by initial listing. Modify the code so that it would include quantity being charged. (Ex: right now, if a user lists 1 product with 3 quantity, system charges $.10; I want it to charge 3x.$10 for the 3 quantity, so user is charged $.30 total).