bed light wiring question?

if im gna wire up the bedlights to the fusebox, also if i connect to the battery can u do that without disconnecting the battery cable? i dont wanna lose my settings and have to redo the seatbelt alarm thing

 

If you are very careful, yes. I don't recommend it though. Any screwup on your part could fry some important stuff.
Are you running it of the lug on the engine bay's fuse box? That's the way to get the most power to the bed. Then you can tap into that for other additions without overloading. You can also use a relay to switch it on and off with the ignition, if you like.
Definetly use a fuse as close to the battery as possible.