Use of conditional tense/sujunctive mood

I am discussing with a friend (over email) the pros and cons of various interview styles. At some point in the email I write:

"Ideally the candidate will demonstrate X."

Then in the next sentence I want to describe, by comparison, what action by the candidate would not be ideal. I was initially tempted to write:

"What would be bad would be if the candidate did Y"

but the bold-text "would be" sounds wrong as used here. Instead I feel I should write something like:

What would be bad is if the candidate did Y"

because I'm saying that [the action that would be bad] = Y, as opposed to [the action that would be bad] would be Y. In other words, I know that the action Y would be bad.

Neither phrase sounds perfect though. I would appreciate any explanation of a 'correct' phrasing! Also I am from the UK, but living in the US so I am interested in usage in each place (if there is a difference). Finally, I apologize if I have mis-tagged this question - it seems to me to be a question about use of either the conditional tense or the subjunctive mood, but this could be wrong.