I know that a relative clause and main clause are formed when you have a construct of [sentence/verb] + noun in Japanese. While attempting to translate the following sentence, I found three of the above construct as denoted by (1) (2) and (3), where the relative clause and main clause meet.
Number 3 seemed suspicious to me and not quite right to be a instance of the relative-main clause construct, so I did some research. This answer says that はず (in most cases) is a 形式名詞 ("formal noun"), which made me wonder if it is possible to make relative-main clause constructs using formal nouns as opposed to normal nouns.
And if the answer is 'yes', is the above instance of はず making a relative-main clause construct? If not, why (in the case it is a formal noun in the above instance, but still fails to make a clause)?