I don't really agree with you about casters being tp heavy. Not sure about healers, but at least mages, aren't really tp heavy for a couple of reasons at least:
1. the damage doesn't scale that much with skill levels, so you can leave them at 50. And since leveling till 50 is pretty cheap.. it's not tp heavy at all.
2. mages mostly spam flame during burn, so besides passives.. they don't have a whole lot to spend tp on that would actually make a difference.
Scouts are tp heavy because they have many different skills to use, whose damage all skill relatively well with skill level, despite damage being often more important than dps for ranged skills. well the exception being s/wd.. since in burn their highest dps rotation is shot spam.
Sorry, I have to disagree with you WRT casters. Casters do have a lot of skills which, early on, need to be upgraded. At higher levels, a player will want to use an Advanced Skill Reset Stone to reallocate TP as their play experience grows and their roles change somewhat.
Note: I'm going to provide links to the class primary skill "trees", and runesdatabase.com has been including probable new skills that won't be available until Chapter V comes around. So, ignore skills that aren't yet available in the game. I am not going to address either class General or Elite skills. Too many variables there, and that makes my head hurt. I'm allergic to pain.
First, take a look at the Mage primary skill list:
http://www.runesdatabase.com/skill/list/4 Now, somewhere along the line, the player has to decide not only *which* skills he plans to upgrade, and how far. It's very possible that along that particular line, an ASRS might be used to reallocate TP to the skills he's decided he *must* or *wants* to focus on. Personally, and just for me, at higher levels I have little to no use for Plasma Arrow and its associated skills. Sorry, but I like to blow crap up, and fire-based skills do more damage. I do tend to level up both Fire and Wind Knowledge, the latter to make TS more effective.
Now, take a look at the Priest primary skill list:
http://www.runesdatabase.com/skill/list/5 Virtually *every* skill on that list that can be upgraded is essential to the classic healer role. So, you're spending TP like water and having to balance the truly beneficial skills against ones which are less useful, or not useful at all. Again, at higher levels, an ASRS is going to be important for reallocating TP to the, again, more beneficial and *needed* skills. "Needed", in this case, refers to skills which are the most useful for instance runs--keeping yourself and your party members alive.
Now, for the Druid primary skill list:
http://www.runesdatabase.com/skill/list/8 Druids are somewhat odd ducks, as they have outstanding single-target heals, a very good group heal, and better better primary damage skills than Priests have. They're a bit tougher to play since they have more singe-target healing and buff skills than Priests do. And, their offensive skills are generally better than those for Priests. Again, as the player progresses to higher levels, an ASRS may be of some use to reallocate TP into the skills the player wants to focus on or upgrade further.
I do agree that Scouts are very TP hungry, and frequently deficient. I've been playing one since Chapter 2, and it's a stone bear to gather enough TP to upgrade even a relatively small number of the available skills to near end-game.
And now, since we're really off-topic, let's go back to helping Gregorii, okay?