The kits in Addictive Drums were recorded in a way that you might call a "standard" way of recording drums. This means that there are close microphones on the bass drum, snare drum, the toms and the percussion in the Xtra slot, but the cymbals were not recorded with close microphones. That is why they don't have their own channels in Addictive Drums. Getting the cymbals to "sit in the mix" is traditionally done by applying effects to the Overhead and Room channels. In the top left corner of the EDIT page you have control over the gain and pan in the Overhead and Room channels for each kitpiece.
When I raise the master to bring in the cymbals I loose control of the rest of the kit, as I can no longer control Cubase mixer volumes.
I'm not sure I understand what you mean. If you elaborate I might be able to point you in the right direction.