Noun phrases and clauses.

that feeling you get when your kid won't let you do your housework.

me stressed at the thought of tonight's traffic.

a salesman who visits a company that makes your dreams a reality in this fantasy story which takes place on another planet.

These are noun phrases, headed respectively by feeling, me, and salesman. Everything else in them is either a determiner, or a clausal modifier of the head: a reduced relative clause in the first, a participle clause in the second, and a frank relative clause in the third.

So these all have embedded clauses within the phrases.

So is it the head noun and the other words and determiners that distinguishes them from being just a dependent clause on there own?

Who ate handfuls of Cheerio's with his bare hands dependent

a man who ate a handfuls of Cheerio's with his bare hands noun phrase

He died in prison of heart failure just over a year later, days before he was due to apply for parole.

He died in prison of heart failure just over a year later, which was days before he was due to apply for parole

What does clausal modifier mean in relation to the example, also?