You mean the keypads for KeepassXC? There is a list of shortcuts for it, but maybe I misunderstood your question.

The database syncs automatically whenever you edit anything, but to be safe I manually create an updated copy and upload it myself to always have an updated copy in case of loss (which has happened to me before with a previous laptop lol).

IF you wanted, it also has a browser extension, just like Bitwarded does

It's definetly a good idea to export a backup just in case. I have a local desktop backup with KeePassXC and every couple of months or so I export the file, encrypt it and upload a copy on proton drive and another on a personal external drive

It can! You can also download icon packs to change your icons with different styles (e.g. a minimal version of your apps design)