"but heaven expels them not to mar its pleasure" line 35- God has placed the indecisive in an area outside of hell, this area is even worse than the first level of hell as members must walk bitten by flies on maggots. Could be a comment on how unfair or odd Dante considered christianity or could represent his views on indecisiveness. Clearly something is off in this world of half-hell. he describes the people as "never having lived" and neither part of hell or his enemies. WHile in hell dante seems scared or pitiful of the sufferers, here he seems disgusted by them.
"crowded in a herd, they obey if he should summonas he strikes at any laggards with his oar" possibly a comparison to jesus (albeit a very violent jesus) as charon seems to be acting like a shepard lashing out at straying sheep. Charon could be the savior of the dead as he is allowing them to cross the river as god has wished, just as jesus guided souls to heaven. So if the souls before jesus went to hell, whered the souls before charon go?
Cantos 4
"note well... the one who carries the sword and strides before the others"- line 71
Interesting to note that in hell, homer carries a sword whereas on earth he carried a pen. Seems as if the poetry he wrote on earth was not enough to save him and bring him to heaven, what other reason could there be for him to carry a sword? After all the pen is mightier than the sword. Literally taken it could mean homers adapting to the dangerous area he now inhabits, however nothing is literal. Homer is portrayed as a valiant knight, which is used to show how dante looks up to him. However it could be a silly childish admiration, as dante is supposed to look up to homer for being a thinker, not a man of action.
"for my demandng thme so pulls my story, to multiply the telling would be too little for the multitude of fact that filled my journey."
Basically dante is blowing his own horn here, saying that his journey is so great and full of FACT that to dwell on his stay with the ultimate poets of history with which he fits in perfectly would be a waste of his valuable parchment and he needs to move on to the important parts of the story which are his journey through hell. This piece is beginning to seem more and more as if it was written at or for the church stritcly, or might be an insight into Dante's cocky mannerism.