I don't really see the point in changing STR/DEX/INT/MND into just "Power" if you're not going to thereby merge armor classes anyways. The redundancy costs us nothing while indicating the gear type in a more at-a-glance fashion. But, neither would I care if they were officially consolidated into that single term, instead of that just being the community term for the resultant Attack/Magic/Healing Power.
And if we're not going to do anything with our Primary Stats anyways, I'd just go with...
- Speed (SkS+SpS+Sprint recharge speed*, with MP instead ticking per half-GCD and fixed GCD timers made to instead scale with the GCD),
- Break (Crit chance + Dodge chance + Parry chance),
- Will (Determination+Tenacity), and
- Spirit (Mastery, with effects dependent on one's job).
Simple and intuitive, but this allows Will to indirectly take over the "Big crits" role so that Crit doesn't self-contain its biggest synergies, while Speed is no longer so self-defeating/inefficient for Casters or users of (previously) fixed-length GCDs, and Spirit offers more variable gameplay effects.
Alternatively, split Tenacity, Piety, and Mobility (replacing Direct Hit) into a separate class of stats, buff the usefulness of Piety to non-Casters/Healers, strip the attack value from Tenacity, and just have those QoL/survivability Tertiary stats (TEN/PIE/MBL) compete only with each other, opposite the throughput-affecting Secondary Stats SPD/BRK/WIL.
From there, just ramp up the effect per point of stat and we might yet see some decent customization of gameplay.