Questions are rather odd entities, both linguistically and logically. A question must have a subject about which information is being sought. That subject is not always self-evident in the structure of the sentence, since there is room for assumption and interpretation between speakers of the same language (which often leads to confusion on the part of foreign speakers, who don't know the conventions).

"Is this a paradox?" is meaningless as a question. The subject "this" refers to the sentence itself, and no further information on this subject is available. A statement is paradoxical if it contains two contradictory valid premises. This sentence doesn't even contain one proposition; thus it does not satisfy the criterion for paradox: therefore, the simple answer is No.
I don't see how it "supports" the following, apparently unrelated, question

"Is this a rhetorical question?"
Again, the subject of enquiry is "this", referring to the sentence itself. No claim is made and no information provided. It's rhetorical or the poser does not expect an answer, and the interlocutor can decide whether it shall remain so by either answering it (in which case, it's not rhetorical) or declining to answer (in which case it is.)

There is no paradox in either one.

Nice. Thank you!

A question is not rhetorical or not. An utterance of a question is rhetorical or not. An utterance of a question is rhetorical if and only if the utterer does not intend to provoke an answer.

"Is this a rhetorical question?"

It the utterer intends to provoke an answer, then the utterance is not a rhetorical question. If the utterer does not intend to provoke an answer, then the utterance is a rhetorical question.

My guess is that the poster intended to provoke answers, in which case the utterance of the question was not a rhetorical question and the correct answer regarding that utterance is 'no'.

I don't see a paradox here.

I think I've seen this one before:

"Is the correct answer to this question 'no'?"

If 'no' is the correct answer, then 'no' is not the correct answer.

If 'yes' is the correct answer, then 'yes' is not the correct answer.

That's a cute-ish exercise, but it's meaningless verbal acrobatics. The question refers to itself, but has no information content regarding which an inquiry can be validly made.