where is the hammer? I will break them down:)
身处鲍鱼之肆,久而不问其臭:it’s from Confucius saying: 与善人居,如入芝兰之室,久而不问其香,则与之化矣;与不善人居,如入鲍鱼之肆,久而不闻其臭,以与之化矣。Your sentences are part of it, and literary meaning is: stay in the fish market long time, you won’t smell the stink. Implied meaning: If you always hung out with bad people, you would realize how bad they are, and will be one of them.
鸠占雀巢:from ShiJing (诗经)。literary meaning: dove take sparrow’s nest. Implied meaning: taking the other people’s place or position.
乞丐赶庙公:literary meaning: beggar take the place of the statue in the temple. Implied meaning: not important people or matter take the place of the important one.
蚕食鲸吞:from JiYun’s poem, Qing dynasty. literary meaning: eat like silk worm, eat like whale. Implied meaning: conquer or invade in anyway.
班门弄斧:literary meaning: play around with the door and the ox. Implied meaning: actually can’t do anything, still show off.
情窦初开:from Qing dynasty, Li Yu’s poem. Means: someone fall in love (with somebody).
塞翁失马,焉知福祸: from a legend story (寓言):塞翁失马。( old man Sai lost his horse). It means: misfortune might be a blessing.
鬼灵精怪: is not a idiom。It’s a noun which means all kind of ghosts, wizards, witches..