SGT, is the abbriviation for Sergeant, which is the E-5 Non Commissioned Officer, (NCO) Enlisted soldier's, rank
I've never seen this on a tombstone but I would assume D of W stands for Date of Wound.
Naval? Aviation machinists mate
AM is Air Medal ARCOM is Army Commendation Medal
OLC is Oak Leaf Cluster
oak leaf cluster american
It often means the native state/country from where the man came from.
AM stands for Air Medical, assuming you are talking about a government issued military marker.
I think so. why else would you be standing at the foot of a grave? unless it's somebody you know, in which case you don't really need to read the headstone every time you visit it. Do you mean 'should you be able to read the front of the headstone?'. In that case, yes: the front part of the headstone is the part facing the grave, so if you are standing on the grave side of the headstone you'll be able to read the front.
It shows that the serviceman was awarded the Army Achievement Medal six times.
TSgt. or T/Sgt.
He was indeed in the military and attained the rank of a sergeant.
An oil based exterior acrylic enamel will stand up to the elements for some time to come.