Vestige-less Binder ?.......

[nonsi]

I don't claim to be an Incarnum Expert, but I have explored it for use in a few campaigns. Totemist is heavily based on Natural Attacks, usually emulating those of certain varieties of monsters. The idea has some merit, but I find that Natural Attack rules are not always the most intuitive or balanced form of combat mechanism, and most characters that use them abuse them, Totemist included, if memory serves.
. . .
Continuing from the Totemist idea, I am reminded of something used in Xefas' Kathodos (Think Avatar: the Last Airbender), specifically the Exceptional Mythos "Elemental-Fisted Pugilist Style". In addition to a number of other effects, this ability allows a Kathodos to used Unarmed Strikes at range, while still counting them as Melee Attacks. This has the added perk that augmenting their ranged attacks and augmenting their melee attacks are one and the same. Something akin to this could work for a Binder that is no slouch at ranged or melee combat. But mostly it is a good example because it is outside the box, so to speak.

Ok, this is where ideas started buzzing like crazy.
I suddenly started thinking of elemental melee touch attacks, improving with level to being able to stretch your arms into pseudopods (increased reach instead of range) that deliver elemental damage, then into elemental whips that entangle your foes and knock them prone, with higher levels enabling you to stomp the ground for earthquakes, summon storms, raise tidal waves, ignite cities…. (AAAHHHH THE POWERRRRR)
. . .
Then I paused for a minute, shook my head, took a big breath and just thought: why not just give it the option of taking elemental form for say 1 round / level per day, broken down as the character sees fit (starting at a certain level, of course).

Hmmm...Let me think on this, I may be able to come up with something, but I want to put my thoughts together properly, and present you something cohesive.

I'll be waiting eagerly, since my well is dry on that one.

Keeping to the Tier 2 realm while inserting an ability-exchange mechanism, or hyper-versatile abilities like Polymorph & Planar Binding will be somewhat difficult. The most defining barrier between a T2 class & a T1 class is options. T2 are roughly as powerful, but less versatile than T1.

Maybe if I limit the exchange to 1 / day (just like with Expel Vestige) it'll be enough not to cross over to T1.

I suppose "of later interest" would've been more prudent phrasing. I find it difficult, if not impossible to go from mechanics to fluff, so fluff questions dominate my interest until they're defined enough that mechanics can be judged in the light of how well they represent said fluff.

Definitely.

I don't think they need to be. I just think that spells, as a mechanical worktool, are inconsistently balanced with one another, so we need to consider what spell effects are appropriate for where, rather than apply blanket solutions.

That's my dilemma – what to make available, when and at what frequency.
I know that if I'll see something I'll know if it works or not.

I, personally, don't like "greater power, but at a terrible cost" as a mitigating factor style. The nature of Min-Maxing makes such things frustratingly difficult to balance. Level-inappropriate effects and abilities (usually) do not become level-appropriate due to drawbacks. This is very evident in the form of Flaws or Hellfire Warlock Shenanigans.

Yeah, I already know that Flaws don't work.
As for Hellfire Warlock – my problem with this PrC is not power abuse, but that it's almost mandatory if you wish to specialize as damage dealer (along with that 1-level Binder dip for Naberius vestige), so there's not really an option there.

If the Neo-Binder is suffering such a detriment for power, fairness dictates that the power should be greater than what someone of the same Tier can get without cost. However, if the cost is too low, min-maxing will mitigate most or all actual effect on the character's experiences, and functionally free power has been gained. If the cost is too high, the option will be ignored if at all possible. It is also difficult to create costs of this form that are truly & consistently fair, so one of the prior two scenarios is quite likely. I would try to put such mitigating factors in the form of opportunity costs, rather than actual character detriments.

If I'd figured the balancing factor I'd have had a class by now.

Arcane spellcasters are also the most notoriously powerful spellcasting classes for a reason. And it has a lot to with those kinds of powers and effects. I'm not saying don't give them those things, but be careful, and be ready to tweak.

Oh, I definitely know there's gonna be some tweaking going around.

I am of the opinion that the majority of abilities for this class (and almost any class, I think) should be at-will. Uses/Day as a universal resource just encourages short work-days, and resource-impact maximization. This type of system discourages consistent performance, and encourages going Nova, which is the opposite of what you have declared desirable for this.

Uses/Day and similar restrictions should be reserved for rarely-used trump cards. Major, high-impact abilities that you want a player to truly think about the appropriateness of using. Even then, I think there are more interesting costs for such abilities. I think that frequency of use & opportunity costs are a better restriction than number of uses, for the vast majority of abilities, though. I advocate At-Will as the default, with Recharge Times and/or Costs for any abilities that shouldn't be spammable (which is pretty consistent with the original Binder class, actually).

I hear you loud and clear.

All in all, I have a lot of ideas fluttering around in my mind about this. Give me a smidgen of time, and I'll try to get them to be something other than word-salad. Maybe word-stew? WORD-STIR-FRY!
...and with that, I must get some rest, and attack this anew in the morning.

Definitely.
Just keep 'em coming and we'll turn this mish mash of ideas into a class to be proud of.
(did I mention you're a saint? )