Gary,
It is possible to do all those things you listed. The DCC guru (Paul) at our club has set up his modules with "routes" controlled by a single "throw" - i.e. you pick "Route 12" and several turnouts all throw to set the route. Paul used to leave an extra throttle at the modules - we use Digitrax, and throwing the turnouts from some of the throttles is quite "keypad intensive" while simultaneously operating a loco...! At the most recent set-up, he was running the turnouts via JMRI's software (I think) as well as monitoring the whole network (LocoNet) from his laptop.
It is possible as you note to take this further and combine it with CTC-type operations, signalling, and train detection.
There are several people with Tortoise turnouts at the club, some operated by electrical switches; only Paul does it via decoders (i.e. Hare).
But all have proven reliable, and there are no reported problems.
I realize that much of this info is now "third-hand" as it reaches you, but I hope that it helps. You might try searching yahoo or google groups for discussion forums specific to the Tortoise and it's various "accessories". I don't know if such a thing exists, but I do know the yahoo Digitrax group is an excellent resource.
Andrew