a guy owns many firearms, but doesnt have any family members, or at least none that know or care about guns.
an emergency happens, the guy dies or is in the hospital for extended period of time, so he cant be at his home to properly secure his arms or house.
can this guy before hand (say years before) get with a close trusted friend who knows about firearms, and write a letter giving the friend legal and total access to go into his home for the purpose of retrieving and securing those arms and ammo into his private care and custody?

lets say this is in Kali, and there are no AWs at the guys house, just some basic long guns and pistols.
would a letter of intent signed by both parties and a nuetral witness (although not looked over by a lawyer) by legal? could this letter instruct the friend to sell the guns n ammo if he felt it necessary? and would this be letter be enough for the friend to legally sell the guns?
i guess you could say this is a Will, but for firearms only, and not necessarily be invoked at death but at a time of temp/perm incapacitation.

hopefully this makes sense, so what say you ?

It sounds like a power of attorney is needed.  Call an attorney for the cost. It shouldn't be much.