Is TP interesting as a mechanic?

[Alaltus]

To be clear:
You'd be adding additional oGCDs (all weaponskills are instant, so I'm assuming you meant off-global cooldown, or essentially abilities in every case?) that you can spent TP on?
Or would certain current weaponskills/abilities be capable of consuming TP for bonus effect? (Possibly spells and caster abilities as well, if we decided to make TP universal?)

Set TP costs, or just a minimum TP cost, and then scaling bonuses with the additional TP consumed when using up all of it at once?

Any particular gameplay goals for this system, however vague they may be? I could try to whip up something to see if it's anywhere close to what you're looking for if you'd like a second take.

Off-global cool down actions yes much like the current Limit Breaks but personal to you. The limiting factor for drg or for all aoes could be that aoes generate much less TP maybe. You don't generate tp per mob you hit but for each action you make that connects.

In XI 1000 TP was 100% and the minimum requirement to perform a weapon skill; weapon skills used all TP no matter how much you had. TP went up to 3000, saving beyond 1000 increased the modifier. Some weapon skills were better at 300% than others like Spirits Within. Weapon skills also skill chained which were a bit like battle regimens; did a bit of extra damage and left an opening for a mage to use a corresponding elemental spell for increased macc/damage.

If the mob gained TP in the same way you can do what many are asking for; break scripted boss fights. Trash are gonna die before they get enough TP but bosses won't and it will add an element of unpredictability that SE already has experience with handling. The bosses will still mostly be scripted but you will also have to be ready for which ever TP action the boss decides to use at random.

"We had the battle down, but then Bayohne started spamming super bad breath!"