Question format for Opinion section
I have no real preference -- both would work for me. Skipping questions will be an option (we won't force answers and will respect anonymity). That said, from experience our community of educators are pretty good at answering these survey questions.
Go with your preference imho :-)
Having thought about it a bit more, the likert scale seems preferable with these so we can get a sense of how strongly people agree/disagree.
I'll reword these questions in the survey and we can see how it flows.