GGACHI

After watching so many stoic or aggressive ML characters, I am rather enjoying the the funny and gentle ML in this drama. He feels like an oasis for the female lead and compliments her character nicely. ML is also very intelligent and humble, hidden under the facade of bufoonery, which isn't typically heroic. However, he obviously adores Amei and she can rest in his uncomplicated honesty as she seeks revenge for the death of her parents. The SML is the typical smart and aggressive ML character. But they are usually paired with more weaker feminine characters in cdramas. Amei as character would likely clash with the domineering SML in the long run, so I don't think they will work out. From the description, Amei will likely leave ML when he becomes emperor anf ride off into the sunset.

Actually, he was trying to get the FL to take charge if the city. He is quite intelligent, but hides it under demeanor of incompetence.

Yep!

Her brother is likely alive as he had left a sword for her in their hiding place when she became a widow. He will probably show up later, like the way the husband now shows up and is added to the character chart.

I don't think there is any symbolic meaning. He just heard the rumor that the widow was meeting up her lover at that place, and so became jealous.

He is her husband. However, he is supposed to be a wild card who's sympathetic to FL.

I think there is definitely romance between the pair as I was listening to the OST at the end of 4th episode. It was a love song, and the way the drama is establishing forbidden romance between the 2nd widow and her lover feels like a foreshadowing of the dangers ahead for our fl and ml. Plot focus will likely be on solving the murders 15 years ago, but the relationship between the Fl and Ml looks like it is already baked into the plot. They've already introduced the idea of FL running away twice, so she can up and leave any time. She is there just meet her brother, and the evil FIL is probably counting on that. This definitely feels like a romantic comedy that allows prolonged push and pull of courtship which is the most entertaining part, IMHO.