Woohoo! Finally got Monastic Marshall. In one kingdom. I'm aiming to get as many achievements in my first kingdom as possible. Kind of like trying to complete all the ambitions in one go really. A super challenge, like the legacy challenge.
I got Clever Swordplay by sparring. Sparring is positive interaction, whereas duelling is a negative interaction. It's useful to build friends, especially if they are your enemy, they will still say 'yes' and you get a positive to the relationship.
For Gruel Hoarder, I had 25 plates of food, all in my inventory at once, but it didn't count. It worked with gruel though (the simplest dish that gives you the -5 tasteless debuff).
It's good to work out the nitty gritty of these achievements, because some of them are bugged, and some of them are extremely vague!