After I realized that Bitcoin Core does not supports multi-user/wallets I'm sadly trying to switch to other clients.
Bitcoin core is great but is intended for a single user as I see it, even if multi-wallets will be dynamically supported in the unknown future .
What would you define as a multi-wallet? It is definitely possible for you to switch the wallet.dat around and use another wallet on the same Bitcoin Core. You can even specify the wallet file as long as it is in your data directory.
For that matter how does blockchain.info or Coppay/Bitpay connect to the blockchain? do they have their own full node(s) clients?
Or do they use a well known bitcoin client?
Thanks in advance.
Blockchain.info likely doesn't use Bitcoin Core or at least its modified heavily, as far as I can tell. For Bitpay, they use Bitcore on their block explorer (not to be confused with Bitcoin Core).