the plot isn't that hard to understand. This guy is loved unconditionally by spirits for unknown reason, and now a group of shady individuals are gunning for his life. What's hard to understand
nana knew she was a noble even if everything about her was commoner-like ( short hair, plain clothes, even the prince didn't recognize her at first sight), was surprised by her being demoted to a commoner when she first saw her and has connections to the other MCs. My bet is on the nun, she's...
storytelling wise it's kinda bad, but if you think about it you basically have an attendant with magical-basically-mind-reading powers that makes your job 1000 times easier and safer. I guess out of all this she's getting financial aid and a good salary but i understand why they did the things...