Mate,
Your sort of on the right track there.
Basically, if you're in a steady hover and push and pull on the cyclic with out making adjustments to the collective, you will descend as you have stated.
The reason for this is because if you've got the cylic in the optimum position for a steady hover, the TRT and the vertical component of lift are at a maximum for that particular power setting. If you then change the cyclic position (and therefore tilt the lift vector to one side), the vertical component of lift (keeping you in said position) will be reduced. This will of course result in a descent.
Have a look at the vector diagram that relates to a steady hover situation again. Tilt the total lift vector over even more and the vertical component of lift will reduce.
Hope this helps,
P68
