When D'Artagnan offers to buy a dress for Jacqueline, she refuses, so he instead offers to buy the dress for his love interest this episode. Except that his love interest works at the dressmaker's shop he's trying to buy the dress from, so what he's essentially saying is, "I'll pay you to sew a dress for yourself" — yet she interprets it as the most romantic thing ever.
107 "Four Musketeers and a Baby"
The Highwayman robs his victims while they're traveling in carriages over a particular road. The Queen's idea to set a trap for him is to tell the city gossip that she'll be alone in her palace without guards, then sit alone in a room by an open window talking to herself about how very alone she is.
1) How exactly does this news reach the Highwayman? City gossip or not, she's a noblewoman; it's not like they run in the same social circles.
2) How is this not obviously a trap and a bad idea? Even if the whole no guards in the palace thing is true, the Highwayman still has to find his way through the city streets of Paris and out to his normal roads without being found out.
3) Why not just put the queen in a carriage and drive her around?
Possible justification: the Highwayman is shown as somewhat overconfident, ignoring a carriage of women trying to get robbed until the Musketeers show up to rescue him and then showing off by escaping anyway, so it's possible he'd try something as rash as stealing from the Queen in her palace precisely because he knew it was a trap. Additionally, charming the Queen herself does help him get a royal pardon when he's arrested and about to be hanged, so it could have been something he'd been planning anyway.
111 "To Heir is Human"
So Celeste is willing to give up avenging her husband's death and the Musketeers are willing to give up the chance to expose Mazarin's evil deeds in order to spare Louis the knowledge that his father had a mistress and a bastard child? That's kind of what royalty did at the time; it's not like it was a well-kept secret.