Caledonian, if you add the premise that some people should be respected, it is a logically valid and necessary conclusion (given that all people at some point have daft beliefs) that not all people who hold daft beliefs should be disrespected.

No, it doesn't. You're ignoring the possibility that respect can (and should!) vary across time. What if the "some people" who should be respected is the set of people who aren't holding daft beliefs?

More importantly, your belief that everyone holds daft beliefs at some point is daft.

You should be more careful about making assumptions.