I think coming at from the direction of setting the CD as the first step in the ability design process, is to come at it from a more difficult perspective, that won't necessarily produce a "finished" product any faster or with less effort.
I'm actually not using the CD assignment as the first step. I'm simply looking for a rough formula which can be used to determine what a pure damage ability should deal in a vague sense as a guideline for setting damage values while designing the intended attack strings in a holistic manner. The closest I've gotten is that all pure damage attacks start off with a baseline 1.0 modifier (equal to the base damage dealt by your basic attack without factoring in procs) and a percentage of a further 1.0 modifier based upon the percentage of the CD compared to a 15 second "generic" CD (6 second CD, which is 40% of 15 seconds, would equate to *roughly* 1.4 "basic attacks" worth of damage). This is a *very* vague guideline since it assumes that the damage is dealt roughly equally across most attacks (so it works for classes like Consulars and Knights but not as well for Troopers which tend to deal a *lot* of damage within a small number of attacks and rely upon their base attack more), but it works to some degree.
The reason why I say this, is that while casting time is mostly just a variable that is being used to set the "feel" of play for a particular ability, by influencing player mobility. CD I think has been set mostly for balance in an after the fact fashion.
I'm actually not paying attention to casting time since it's more of an abstract applied to lengthen the GCD and moderate damage. When looking at abilities, I'm actually looking at damage per GCD and only within actual practical application (so I'm not looking at TkT for Shadows except for Kinetic Shadows and, only then, when you have 2 stacks of Harnessed Shadows; since it's a 3 sec cast, I'm functionally dividing the damage by 2 to represent the fact that it consumes 2 GCDs).
I also recognize that it's a holistic assignment in the first place, so it's not like CD is deterministic for damage or vice versa. You have to consider the whole of the attack rotation/priority rather than the individual abilities themselves. I'm simply looking at a guideline for a baseline,
High Impact Bolt/ Project are essentially the same ability. The same could be said of TK Throw and Full Auto.
I'm not really seeing the similarity between HiB and Project: Project costs a crapton to do mediocre damage and a little stun. HiB deals a lot of damage without the stun and costs comparatively less. TkT and Full Auto are roughly similar however.
There are some "standard" archetypes for attacks that all classes use: Ion Pulse, Double Strike, Slash, and the like that are baseline consumers that deal more damage than the basic attack and have no CD; Stockstrike, Blaster Whip, and Blade Storm that are on CDs but deal substantially more damage for their cost to make up for it.
Those are the abilities that are the less efficient abilities in terms of cost/ GCDs/ and the amount of damage done, such as Mind Crush & Charged Bolts.
Charged Bolts actually has more in common with Disturbance for Sages, Double Strike for Shadows, Ion Pulse for VGs, Quick Shot for Scoundrels, and Charged Burst for Gunslingers than it does with Mind Crush. Mind Crush is a "special" attack (generally reserved for proc'd effects making it effective) whereas Charged Bolts is a baseline consumer (since it tends to proc other attacks rather than getting improved by various in class procs).
1) For this comparison to mean anything, you have to convert the resource of each class to a common denomination.
2) Any abilities that require a proc to be used, or consume a proc during their cast ~ cannot be directly "valued" as a stand alone ability. The relative value must be inferred by subtracting the values of the other abilities that enable them to be used, after calculating the value of the whole "string" and adjusting the derived value by the ratio of it's frequency.
3) The 1.5 GCD is used for the casting time of an instant.
4) The regen rate used, has to assume that the ability is being used while regen is at the baseline value. As soon as you throw in variable regen modifiers like the concentration proc, regen dubuffs, emergency regen abilities, or being at a low regen level for trooper/ scoundrel ~ these values just go all kinds of wonky. You end up with sepperate values for every ability used with different stacks of buff on self, debuff on target, etc. The base regen value used for the knight has to estimated based on how much focus is generated in an average 60 second period of mixed ability usage.
5) You almost have to assume that DoTs are refreshed at the optimal rate, and not cast on multiple targets on CD.
6) Mitigation effects from abilities have to be quantified somehow, even if it's just the dps that is eliminated by a KB against a melee target. The good news is that you could actually compare the value of a stun to a dps ability or a heal.
I've actually done all of this already except for the last. Since the mitigation effects of certain attacks only really take place in tank specs, such benefits are factored in as part of the survivability calculation based upon the use rate of the given attack rather than as an abstract attached to the damage/threat balance functionality of the attacks. As such, rather than trying to find some way to balance the 5% acc debuff on Force Breach for Force Sweep for Shadow and Guard tanks, it's simply considered to be a static benefit attached to the ability in a mechanically arbitrary manner: it wouldn't matter which ability it was tied to as long as it was tied to *some* ability such that it could maintain the same uptime. The quantification of non-direct mitigation benefits (such as KBs and conditional stuns) are less significant than you might imagine, only really being present for flavor (no one really cares that Project, Force Sweep, or Full Auto ends up stunning the weak and standard targets since those targets are largely unimportant and can be beaten by just slamming them with your basic attack ad nauseum; it's just a tangential secondary benefit that makes some degree of sense to have on certain attacks without really making a substantial balance difference; the "real" stuns are less concerned with their damage and actually follow pretty standard formulas for duration, range, damage, and cost based upon the PvP balance equations).
Target resistance to specific damage types completely rebalance the worth of many abilities.
The variation in damage type and attack type is actually relatively simple to quantify: using the standard ~35% K/E DR that ops bosses get allows you to "increase" all I/E damage by a factor of ~1.5 to reach the damage equivalence; attack types follow a similar formula insofar as you can roughly quantify the chance to miss (or itemization lost to make up for said losses) and apply a roughly 5% higher damage to those attacks to reach vague parity.
I doubt very seriously any MMO class has ever been designed on paper, that made it into a finished product unchanged. That's the whole reason why they have play testing. That's why no one can really predict how changes will be recieved by the players, or what the players will do with those changes in the meta game. And it's why MMO "balance" is always an ongoing process.
And I highly doubt that any MMO class was designed purely in the abstract without ever first being built upon a foundation of paper. The pure theory represents a baseline of performance and provides a structure for the remainder of the class to grow through the organic process of playtesting and simulation. The quality of said pure theory development has pretty substantial long term effects: just look at Guardian tanks compared to VG tanks or Shadow tanks; it's readily apparently that Guardian tanks didn't really have much in the way of on paper development because most of their functionality is just thrown together from ability archetypes in previous games and then modified later on to achieve numerical balance without much thought towards how it actually plays. Well thought out classes are readily apparent based upon their elegance of design. The intent would be to design a class with abilities that work together in a manner such that the end result would work together seamlessly without the rough hammering that would be required otherwise.