"He almost decided to eat half the pizza for supper." Is there a misplaced modifier in this sentence

Yes, the misplaced modifier in the sentence is "almost." It should be placed immediately before the verb "decided" to clarify that he came close to making a decision. The revised sentence would be: "He decided to eat almost half the pizza for supper."

"My boyfriend made it clear why we were breaking up on Monday." Is there a dangling modifier in this sentence

No, there is no dangling modifier in this sentence.

"My boyfriend made it clear why we were breaking up on Monday." Is there a misplaced modifier in this sentence

No, there is no misplaced modifier in this sentence.

"The paint job that they did yesterday is not dry." Is there a misplaced modifier in this sentence

No, there is no misplaced modifier in this sentence.

"She only liked frozen strawberries." Is there a misplaced modifier in this sentence

Yes, the sentence "She only liked frozen strawberries" contains a misplaced modifier. The word "only" is modifying "liked" instead of "frozen strawberries." A better way to phrase this sentence with the modifier correctly placed would be: "She liked only frozen strawberries."

"The doll belongs to my cousin whose head is missing." Is there a misplaced modifier in this sentence