How can I use a 5200 mAh Li-Po battery to power multiple things?
It's safe for sure, just be careful not to short anything, Li-Po can output dozens or even hundreds of amps - that might cause fire hazard. Best idea that comes to my mind is to use some kind of power distribution board that are used e.g. in drones. That will make a couple of +/- pairs that will allow you to distribute it over your device. Here's is picture how it might look like.