This FR is valid.

It's not contradictory, because it doesn't demand the impossible and, assuming 'not repeat any word' means 'not repeat any word used within itself', satisfies its own restriction; nor does it assert the impossible.

It's not inconsistent, because it amuses with its strange child-rearing advice, and dryly asks about Moffat's plans; it mentions exactly one rodent; it mentions a dairy product; and it contains the apparently incompatible concepts 'being chief writer' and 'never writing again'.

It's not illegal because, although it appears to attempt to overstep the limits of what an FR can do by saying that FRs 'must not' repeat a word, I've interpreted 'must not' as 'does not' in the past and I stand by that interpretation.

It's not unreasonable, because future FRs remain possible, and it's not irrelevant because the round's not over.