I posted this on the HP Pass thread, but I think it might benefit from a separate post, since not everyone reads lamania discussions and likely it will get buried in the weeds.
One thing that comes to mind is possibly offering a free feat selection to classes on first level. Make this feat selection a path like how many races or deities are selected. You choose melee, spellcasting or ranged specialty. Depending on your choice, you unlock various PL benefits for each class. In other words, certain class PLs can be specific to that playstyle so that they all have value to the selected playstyle. For example, wizard could be spawn screen cast x3/day, or +1 to hit for range per stack, without changing its current benefit to casters. Hmm. But it would have to be all in at feat selection to which path so there is no picking and choosing benefits. With this in mind, it would be easy to add additional HPs to melee classes without impacting other playsyles. And it would also be easier to implement where other bonuses go where intended since you have to make a playstyle choice and potentially lose out on caster or range benefits by making a selection to go melee or vice versa, which eliminates the issues associated with EKs, Warsouls, ES locks, etc. Heck you could even add certain benefits in EDs, or class or racial enhancement tree and get rid of many multiselectors.
I could even see imbue dice being tied in somehow to this feat selection and especially with melee, you can further segregate choices in to your fighting style, without the devs worrying if caster will pick up certain fighting style feats to gain unintended benefits.