The Executive was well capable of this. Remember, it was only delivered with one font. There were multiple-width space and backspace keys, and you could accurately move the carriage to do type-setter-like work. This was a professional machine, designed to be used by highly skilled typists.
Somebody's going to reproduce this thing on an old typewriter, and then we will wish we concentrated on the obviously forged signature, fake P.O. box, and suspicious content of these docs.
What you say is true, BUT, since LTC Killian could not type, it is highly doubtful he produced these himself - especially on one of these advanced machines. It is also highly unlikely that a TANG unit would have had equipment suited for publishing work (what were they going to publish? [except of course these memos . . .]) As to the PO Box - it seems it is legit - just it's use on official documents is "fishy".