Long-term Design Questions Best Answered Before 5.0

[Shurrikhan]

For those (at least vaguely combat-related) questions that probably ought to have been answered a while back, but get more irritating with each expansion they're left unanswered.

I'll start, and then shortlist the questions here. (Please write the core question in bold, if you don't mind.)

What's the point of TP, really?

What, if anything, SE will be doing to introduce a new healer that isn't a copy of WHM + SCH + gimmick (like AST is) in light of the above.

What is the point of the resistance down debuffs, and why are they still in the game?

Why create a ["selfish" or independent output] job meant to be nothing more than raw damage...and not allow them to put out enough raw damage to surpass a utility DPS job?