He’s your current employer, and you live in his house.
Not a red flag. Not for you at least. As the person in the higher class, he is the one with the most to lose. For you, there is nowhere to go but up.

He lies to you about who he is when you first meet.
Not a red flag. This is called keeping the mystery alive, and he is smart to make a habit of it early on.

He accuses you of putting a spell on his horse.
Not a red flag. Insisting that the person you like has used dark magic is actually a very common method of flirting. All the kids/ grown men are doing it. Other versions of this technique include accusing the person you like of being a little fairy, accusing the person you like of being a little elf, and repeatedly referring to the person you like as “an unearthly thing.”

He asks you if his forehead pleases you.
Not a red flag. Data show that poor regard for a spouse’s physiognomy — and specifically the frontal brow region — is a frequent source of marital strife. So, if he’s asking this question, he is probably starting to think seriously about the relationship.

He brings home another woman and spends all his time with her.
Not a red flag. Being a true gentleman has many requirements. Sometimes, you have to use the little fork. And sometimes you have to house another woman (and all her friends and family) for several weeks, paying attention to only her. Do you want your future partner to be a part of high society or not?

He disguises himself as a fortune teller to learn your secrets.
Not a red flag. Because he did come clean about it near the end. And when was the last time you put this much effort into date night?

He gets engaged to trick you into revealing your feelings for him.
Not a red flag. How else is he supposed to know how you really feel? By asking you directly and accepting your response in earnest? No. Courting another woman to the brink of marriage is the only possible way. And, unfortunately, too few are willing to go to the trouble these days.

He describes you as “poor” and “plain” while proposing to you.
Not a red flag. Relationships shouldn’t be built on lies, and it is rare to find a partner willing to take that principle and fully commit to it.

He asks you to sponge drops of blood from a guest’s head after they are mysteriously attacked in the middle of the night. He also asks you not to tell anyone about it.
Not necessarily a red flag. Just because there are weird goings-on at his residence doesn’t mean he is responsible for them. I mean, obviously, you have questions. But as his lover/ employee, you are also eager/ contractually obligated to help. Ultmately, if he can offer some form of explanation for the incident, this is probably something you can work through.

He is secretly keeping his mentally unstable wife up in the attic, and she is the person who has been getting out and attacking people.
Okay, yes. This is a red flag. But not because of what it says about his character; it just means he’s not technically eligible. You’ll need to wait things out until his current wife sets the house on fire, leaps off the roof, and makes him a one-handed, one-eyed, but officially available bachelor again.