Hi,
If you are generally just hiking trails, you have safety overkill for sure.
Find a headlamp or flashlight that is less than 2 oz. I think there may be some on sale right now at Campsaver, REI Outlet, etc. (Photon is also sufficient light for camp, but I don't find it easy to replace the battery, so what I carry is a bright, 1-oz. flashlight. On a long trip, an extra flashlight battery or the Photon is my backup.)
Phone: Google/ask ahead about the area you'll be in, does it really have cell reception? 95% of the places I hike don't seem to have reception once you get 1-2 miles from the trailhead.
If you *do* get cell phone reception, and you want to bring it: Leave your camera behind, and use your phone to take pictures.
GPS units are very heavy. Learn to read topo maps instead; bring your map/compass. Or, download a GPS program onto your phone (I admit I don't know much about this) and use it only in emergencies, to preserve the phone battery.
PLB: I would consider carrying one of those, but only if I was doing a very long cross-country hike by myself. Consider, instead, just giving your emergency information and a detailed itinerary to a trusted person who will call for a search if you do not return by x day. If you are staying on trails, it's very unlikely that nobody will happen along to help you within the day; and if you are hiking x-country with a hiking buddy who has good skills, that person can go out for help if you get hurt.
– Elizabeth