These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Designated Hero and Designated Villain: Excepting one or two members of Marsile's forces, the Saracens don't really do anything evil over the course of the story; their behaviour is in fact, nearly identical to that of Charles' forces.
Except, of course, Marsile's previous murder of Charles' ambassadors, his plotting the treachery against Roland, and Baligant's planned invasion of Charles' kingdom and the whole West.
Fridge Logic: Charlemagne is described as 200 years old. His sister's son Roland can't be more than 30. How exactly does that work?
Ho Yay: Roland's supposed to be engaged to Olivier's sister Aude, but he seems to like Olivier himself a lot more. He doesn't even think of Aude as he dies, but when Olivier dies Roland weeps and hugs his "ami's" body to his chest.
Roland himself is sort of God-Mode Sue. In the song, he represents the figure of the brave flawless Christian knight, kills lots of Saracens and he's only killed by blowing a horn. The real-life Roland was a mere nobleman in the army of Charles and was not related to him.
Narm: Having the hero die not from getting killed in battle but from blowing a horn hard enough that his skull bursts is a little hard for modern audiences to take seriously.
They Just Didn't Care: It's worth noting that the battle of Roncesvalles wasn't even fought against the Muslims, that Charlemagne did not live to 200, and that clergy were banned from fighting.
Unintentionally Sympathetic: The Saracens are liable to come off this way to a modern audience, especially Baligant and his men, who played no part in Marsile's treachery. YMMV, of course, and it may not even be entirely unintentional.
Values Dissonance: In a surprising example of a clash between early mediŠval and later mediŠval values, Archbishop Turpin tells Roland that a knight who is not brave, "is not worth 4 cents, and ought to be in a monastery, praying every day for our sins" — because all bishops think more highly of knights than monks, right?
After Charles convicted Ganelon of treason, not only is he sentenced to death but so are thirty of his relatives who sincerely defended him. Yup, this is an example of collective punishment where a whole family is held responsible for crimes by one member (like the story of Achan in the Bible). This is of course very unfair for modern audiences.
Woolseyism: The Swedish translation by Frans G. Bengtsson changes the assonances to a complex rhyme scheme and adds some Scenery Porn not in the original. Some people consider it an improvement.