The ancient tactical writers (Aelian etc.) do place the officers in the front of the phalanx.
(Now, all the extant tactical manuals date from Roman times, but there's AFAIK no reason to distrust them on this point; they presumably got the information from the Hellenistic-era predecessors they mention. Also, in the Classical era, when even the high command were on foot, there are examples of victorious generals being killed in battle, implying they led from the front.)
Yes, phalanges did carry standards.