Dangerous?

You don't want to add a lot of load to the OEM wiring. It was barely adequate for the OEM duty.
If you want that fuse panel hot at all times as shown, pull a separate supply line from your starter relay to it. With inline protection out there at the starter relay, a maxi fuse, a fusible link, something.
If you want that fuse panel hot only at switch on, same as above but, the supply line would go through a relay to get to the fuse panel. Any switched circuit, beyond your ignition switch will signal/close the relay, power up the fuse panel.
Typical Bosch relays are rated at 30 amps which may be sufficient where high amp accessories like electric fans are on separate circuits and their own relays. In those cases your added fuse panel is simply serving the 10 amp signal lines to those relays. Every one of those relays would get a root source similar to this fuse panel.
All the same as what we find in newer vehicles, lots of small wires, low loads inside the cab. The big wires, high loads outside the cab.