I will try answer what I can in the most layman type of way.
Wappler is not really a WordPress style program where there is like a builder or blocks that can be kind of dragged and dropped, it is more of an amazing step up from writing your own code from a blank piece of paper to now having a UI that can do that all for you, so there are predefined modules that all fit together perfectly so they can generally work as stand alone or together and all talk to eachother properly.
You can create any admin panel you like with dashboards, and graphs, with full database integration to fetch and write/delete/update anything in the database. But this is a build it yourself the way you want it solution.
You can add role management, the component for security / login supports it perfectly, but you design the database, work out the roles etc. and then tell Wappler what you want each piece to do.
Multilingual support, if you mean is the Wappler app downloadable in multiple languages, I am unsure to be honest.
If you mean can it help create websites and apps that support multiple languages, then yes, either by designing your app that way yourself, or by using multiple third party services via API that can do it for you.
Yes it can create a shopping cart, but no actual module built in, you have to create it yourself, and make it work exactly how you want, by adding multiple layers of server actions, and front end components, or API connections to various sources. It has great prebuilt stripe modules which makes it so much easier though.
Not sure what you mean by tools to manage payments, but you can design your own in any way you like, fast and easy because Wappler does all the heavy lifting.
Sadly we hardly get any people sharing their full applications as most of us are building them for clients and due to security etc can not share them.
To be honest though Wappler can do anything, some things are just there out of the box, while other things you can integrate yourself in a Wappler way and allow it to integrate with all the other tools already in the App.
Hope this helps a bit.