Nylon vs. Steel. string gauges...

Does the heavier gauge of the strings of a classical guitar mean that the strings need to be shorter, which also means the length between the bridge and nut shorter to make the notes produced the exact pitch of their steel string counterparts?

The short answer is no. String gauge has only a subtle effect one the "speaking length" of the string. You have to remember that you cant really change the string length (intonation aside) The guitar is designed to have the frets measured out to divide each interval as close as possible.