Question Need help with a really ambiguous conversation with many slangs I don't understand (Princesses talking about MC while they're travelling to JP)

[zeroh4nter]

Context : MC's father recently died due to illness (or overworked ) .His father is a close friend of a King in a certain small European country ,and he helped the King to rebuild this country after many civil wars.
After he died ,the King felt guilty and want to make up for his son in JP ,by ordering his daughters as Princesses to fly to JP and marry MC (the King refers to this as "The Marriage of Redemption/ 罪滅ぼしの結婚 )
Now the princesses are chatting about MC ,wondering what would he look like /what's his personality..... etc . There are a few hard sentences for me ,so appreciates if someone can explain their meaning to me o/

フローラ「きっと素敵な方よ。鏑木様自慢のご子息ですもの」 (鏑木様 is Mc's father)

エイミ「でも、サクラちゃんが『痩せ細った野良犬のような印象の青年だった』って言ってた」 (サクラちゃん is their maid)

シェリル「ぷっはははは、ウケる」

アニス「笑いごとではありません！　おいたわしい……鏑木様を襲った災禍は当家の繁栄と表裏なのよ」

エイミ「罪滅ぼしの結婚っていうのもちょっとね。苦労の反動とかで威張られちゃったら息苦しいなーとかも考えちゃう」 (I don't understand this part)

エイミ「没落したボンボンって闇属性感ない？　ママーって叫びながら顔とかかきむしりそう」 (like her sister below , i don't understand what's she meant here either ==')

アニス「あなたの言うことは時々よくわかりませんわ」

シェリル「てか、気に食わない相手だったらどうせ嫌がらせして追い込むだけでしょ？　エイミはさ」

エイミ「あっははははは」

アニス「否定して！？」 (I don't understand this part too)

フローラ「みんなの話を聞けば聞くほど不安になるわ～」