You might consider replacing the velcro closure and / or tying the whole thing shut for security.
Maybe it's better to wrap some paracord around it to prevent that.
Knife - I'd replace the knife with something flatter and lighter. Spyderco?
Wich one? The Buck in the PSK or the Night-Hawk?
Back-up firemaking: A small flint, and acredit card sized fresnel lens
Already in the PSK
First aid --Perhaps a sanitary napkin packed in the middle to stop blood loss
FAK is carried in hiking-kit and as part of EDC.
Misc -- Flagging tape 1-2 M, SPF #30 chapstick -- can be used on your nose for sunscreen
Good idea!