BOAC,
The aircraft can be, and sometimes MUST be, "de-rotated" (I prefer a "decrease in target pitch attitude"), to maintain a positive rate of climb. For example; if the rotation is to the all engine operative target attitude, and an engine failure occured at the rotation or shortly thereafter, then a positive rate of climb could well result. However as speed started to fall below V2 a decrease in pitch to the engine-out target attitude would be required to maintain airspeed and, ultimately, a postitive rate of climb. In the all engine case, over-rotation may also require a decrease in pitch attitude while still maintaining a positive rate of climb.
Apart from all that, lesson #1 states that POWER + ATTITUDE = PERFORMANCE. QAR ASR would like to demonstrate this to you! In all types rotation is always to the "target attitude" and then performance is checked and attitude adjusted as required by performance. Performance can only be indicated by performance instruments (in this case some combination of IVSI, Altimeter, RA or VSI). Also more than one sustained indication is required, especially in older types where instrument lag and VSI rotation error (rotational forces leading to an indicated rate of descent) may be a factor. Flight manuals, or training manuals, will give this information for the applicable type.
As for "clicks", well it's an interesting theory, but those clicks could be loose objects falling from the galley benches or whatever. Reminds me of a reject at moderate speed when a mobile phone went off during the take off run! The guilty party was in the jump seat and closely related to the skipper!