Should This Not Be Meaning?

"Should it not be" means the same thing. It forms a start to a hypothetical with the same meaning as "If it were not blue, I would not like it."

Should be not or should not be?

They are not interchangeable. "Should not to be" is not grammatical. If you want to use "should", just say "should not be".

Should not be use in sentence?

You shouldn't be cooped up with a sour old man every evening. I shouldn't have been surprised. I am not saying if you enjoy manual labor and being exhausted at the end of the day, you shouldn't do it. But they shouldn't be doing this.