@Ratte such tools shouldn't have an IHM.
Using fsck should eventually happen in an automatic way when there are no possible risks. Otherwise, too risly to have a GUI for that.
Partition resizing / backup : no partition resizing, recalbox is not GParted. And partitoin resizing is something that works very bad depending on the FS of the concerned partition.
Partition backup : the only one that is worth is the share partition. https://github.com/recalbox/recalbox-os/wiki/Use-an-external-usb-storage-device-on-recalbox-(EN)#optional--sync-your-usb-key-with-your-sd is more than enough, despite we could eventually add this in a menu, I agree. But that's not the main concern for now.