The OP was asking for recommendations. Certainly recommending any particular book or author does not have any negative implications for books and authors not recommended. Also, a comment to the effect that such and such a book may have questionable content is, without question, l’toeles.
EDITED – seriously? Did you read what the Chofetz Chaim says about the criterion for considering something l’toeles? Do you think speaking anonymously in a public forum would be included?