Crossword puzzle clue "if i were in your"

Particle physicist whose findings were first accepted by Einstein, but later were shown to be fraudulent

"Wish you were here—__ were there"

Yell at your parents for not making the soup salty enough because your crush told you your mouth looks too funny to kiss, e.g.

Performed in a way that made your parents leave your school play in the middle of your solo :/

"... your flashes of merriment, that were wont to set the table on ___?" (Hamlet)

"Live ___ day as if it were your last"

His first words to Alice were "Your hair wants cutting"

Classic Mardi Gras song that begins "My grandma and your grandma were / Sitting by the fire"