Chuck,
We are looking at these alerts. Truly, we need to separate out into Terrain, Obstructions, Airspace, Info Alerts, Traffic, etc. Right no several are mixed and we should allow for more isolated alerts. Example I'd like to see Terrain off, but keep Obstructions on. Likewise, I'd like to turn Info Alerts like 500', Entering AirportZone off, yet while keeping the Airspace alerts on. It's on the wishlist of improvements, but no progress to my knowledge has been made on this. We are working on 9.4 at this time, which will include Winds Aloft, Winds Planning with new Weather Imagery and other enhancements.
Stay tuned, as we have to target these request based on demand, our current development plan and insert where we can without disrupting or delaying the flow to much. Thanks for your patience.