A magisterial statement which is not intended as doctrine or dogma does not fall under the notion of infallibility.
Could a Pope make a statement, not intended as doctrine or dogma, which is in error? Asked and answered: yes.
Not every word in a papal document is a statement of doctrine or dogma. Therefore, by definition, not every word in a papal document is protected by infallibility.
Now you’ve moved on to a different question. Earlier, you were asking about assent to doctrine and dogma. Now, you’re asking about assent to assertions that are neither doctrinal nor dogmatic. Yes, there are teachings which fall outside these categories. Yes, Catholics are called to obey the teachings found in encyclicals, even if they’re not, strictly speaking, ex cathedra statements.
Correct.
Even if the statements aren’t intended as ‘irreformable’, Catholics are to assent to them.
It would be important to look at the statement in context, in order to discern what exactly was being said.