I've already been in discussion with many many different payment providers and I'm getting tired of endless meetings and discussions, which in the end end up that the support or their sales department was hiding a flaw in their system / confirmed one of the features below that is actually not possible; and you have to look for another provider, reprogram the entire integration with a new provider, etc.
So I wanted to ask here; does anyone here know ANY payment service provider which is compatible with a PHP + MariaDB backend, and with mobile apps as well (via Rest API calls) that have all of the following features:
Secure.
Register a Credit Card for a customer via a custom form submission; ideally send data to payment service provider via js, receive an according token from them, and store that token within your DB. Like this, your own server does not have to be PCI compliant.
Every time a customer X clicks a specific button on your website, after authenticating the request on your backend, use your token to trigger an according payment within your backend (with secured public key authentication, etc.)
Every single payment the customer X realizes has to be only authorized first ( = validate card + verify that clients has the funds, + freeze them on the card), and captured after the customer X received the booked service, days later.
The authorize and capture mechanisms must work for every single payment with the obtained payment.
refunds of captured transactions must be possible.
The KYC procedure of service providers who receive payouts has to be possible for individuals, not only for companies (believe it or not, some providers only provide company profile possibilities for payouts..)
The Service provider must ideally be internationally active, i.e. with low currency switch fees.
Split Payments must be possible (e.g. marketplace - style, customer pays fee for service to company, company takes off commission and forwards rest to service provider)
Not sure how the PHP + Maria DB has anything to do with your inquiry. You are calling a RESTfull API, call it with any technology you want.
Most of Your requirements are pretty straightforward and can be answered by many providers.
The challenging part on your question is more on the international market place part. Which mostly depends on the KYC you mentioned, and highly depends on the country the merchant is in and type of goods you sell.
KYC for market place sellers, payout methods to sellers and so forth are heavily regulated and might be complex in multi country mode. In your search I would explore this topic in depth.