I'm pretty sure there is something "like" this already, but after a thorough search, I could not locate anything. Is this even possible with the new interface rules? The only thing being modified on the fly are the check boxes, and I guess I'd have to live without being able to control them then.
YATA (Yet Another Totem Addon), builds and updates a macro depending on the 4 totems the user chooses he uses the most. The macro is automatically updated (out-of-combat only, of course) when another totem is selected.
Fo your Addon Idea, the following should be doable:
1. the checkmarks can be implemented in FuBar/Dewdrop right-click screen.
2. make three macros: Burn2min, Burn3min and Fullburn and update these when a checkmark is toggled.
3. Using #showtooltip, you would be able to see the cooldown of at least some abilities.
4. To show cooldowns, you could start some custom-bars in NECB or BigWigs.
5. Also, "Call for Bloodlust/Heroism" can be done with just a macro, but because it doesn't involve combat-actions, there are no restrictions on this when implemented in script.
Estimated Time to Death already exists, check TimeToDie.
DrDamage does some calculations on Estimated Time to OOM. Fairly easy to implement.