Hi @MHlavacka ,
1. Depending on the Hub our client has, we will use Serverless functions. But must of the times, our clients do not have the required Hub, so we use an external application instead. You can write that in PHP and host it on a server, but we use NodeJS with Express and host it on Heroku to communicate with HubSpot. You could also create an integration, but that code is not hosted in HubSpot, just uses oAuth to communicate with HubSpot. So you would need to host that code externally as well.
2. Backups are currently not available. It is a much requested feature, but is not available yet. Right now, the only way you can create a backup of certain content types, is by using the export functionality.