In the beginning of the book d'Artagnan is repeatedly compared to Don Quixote. It's easy to see why since they're both poor nobles who get into ridiculous fights for their honor. They even both have ridiculous looking horses. The differences between them however are first made clear with two clues. One is that while many people find d'Artagnan's horse ridiculous they don't laugh since he himself is ferocious rather than proud. Secondly while Don Quixote is always trying to create a magical balsam for his many injuries d'Atargnan actually was given a medical balsam by his mother. These clues show us that d'Artagnan unlike Don Quioxte has the innate dignity and luck of a classic hero.
The Musketeers are most famous for their sword fights, but at the bastion of la Rochelle they have a lot of muskets, and show great proficiency with the weapon... Because that is their real weapon: the Musketeers are a part of the Maison Militaire du Roi (the Military Household of the King) founded precisely to grant the King the protection of a musket-armed dragoon unit, but unless they're in war or exercising they don't carry the heavy and cumbersome firearm around. Swords and pistols, on the other hand, are their sidearms and much easier to carry, so they carry them all the time.
