Although they all mean the same (i.e, "walking back and forth"), I prefer 彷徨 over other variants listed above. The radical彳 "small steps" (小步也), which is often associated with words related to "walking" (e.g., 行, 往), is very fitting here, and so we have either 彷徨 or 徬徨. I don't like 徬 because it means "walking alongside" (附行也), unable to capture the nuance of "back and forth". 彷徨, on the other hand, is the name for a two-headed snake-like creature (狀如蛇，兩頭, 《莊子·達生篇》野有彷徨). One can easily imagine a two-headed snake walking back and forth in hesitation; one head wants to go this way, and the other wants a different way.仿偟, 彷徨, 徬徨, 傍偟, 旁皇, and 方皇.
How is it that this word's 彷 sounds like P instead of F? Wouldn't it be just like 傍偟？
The sound change occurred in ancient Greek (Φ), not in English. The English words were coined with Greek roots and were pronounced with a /f/ at the very beginning. On the other hand, what occurred in Chinese is a conditioned historical sound change.By the way, p sound in many English words has also changed to f sound, like phone, phonetics.
Are you sure it was pronounced this way from the very beginning when ancient English borrowed these words from ancient Greek? I am not sure, so I am open to any idea. I know many consonants and vowels in English have changed over time.The sound change occurred in ancient Greek (Φ), not in English. The English words were coined with Greek roots and were pronounced with a /f/ at the very beginning.