During game play, the only time the game should need to access the CD is for the blessing ceremony and end game videos. Make sure you shut down all non-essential programs (ie anti-virus) before starting the game, particularly anything that monitors optical drives (auto-play extenders, etc).
For minimizing during startup, you could try setting the game resolution and your desktop resolution the same and see if that helps.
With the patch installed there is a configuration file edit to skip the intro videos (see
here), which might help (you will not need the play CD then, except for the blessing ceremony and end game videos).
There should not be any hissing sounds, except maybe with snakes.
Did you check the computer / motherboard manufacturer's site for updated drivers (onboard audio, chipset, etc)? There may be updates even though the computer is new.
Try lowering your hardware sound acceleration a notch, or even disabling it completely (click Start | Run, type in dxdiag and hit Enter, then switch to the sound tab).
Do you have a multi-core processor? If so you may want to try setting DD to only use one core (it is only able to utilize one anyway).
Sound errors with static - maybe fix found! 
