You're right. These are embedded clauses, specifically, relative clauses. If you could use a relative pronoun and a be verb/linking verb followed by present/past participles (which are ending in -ing or -en/-ed), then it would make more sense to you.
The next time you see an extra verb (in -ing or -en/-ed ending), it probably means that there is an embedded clause. Then, if you see a noun before it, it could mean that it is a relative clause.
I think they use reduced relative clauses (without overt relative pronouns) to easily state an idea without the need for repeating words or using unnecessary words.
I can't think of many adjectives that can be used after a noun because typically adjectives come before nouns. The only adjective I can think of is "galore" that can come after nouns. For example, "In the festival, there will be competitions galore." You wouldn't normally say "*In the festival, there will be galore competitions." Thus, this position for adjectives is very rare. However, if you are considering relative clauses with adjectives, then this position is possible. For instance, "The boy quick to address the question was penalized by the quizmaster." (The boy who is quick to address the question was penalized by the quizmaster.)
Hope that helps.
Student or Learner