Aldarc
Legend
Don't let some of these comments discourage you. I would also consider asking around about the system on Paizo's forums, if you have not done so already. This forum leans pretty heavily to the 5e side of things. That said, you have listed a number of the adjacent "d2010" games: e.g., 13th Age, SotDL, etc. So I would consider looking in a similar vein of d2010 games.Well that seems a resounding no, so what system do people recommend that allows varied mechanical character builds, reasonable tactical combat and a nice choice of character options on level up, while still maintaining a semblance of balance?
Not interested in OSE stuff, tried em and we found stepping back too jarring, 13th age was ok but as I DM I hated the icon integration, and shadow of the demon lords setting wasn't our style. Am I heading back to the almost impossible task of 4e ( playing without an electronic character builder is so much fun)
There is the Cypher System by Monte Cook Games. It's super easy to run as a GM. Tactical options are more limited from the player abilities than what you find in D&D. The greater tactical options come from the single-use Cyphers (e.g., scrolls, potions, talismans, etc.) that players may find in their journeys.
Rob Schwalb is working on Shadow of the Weird Wizard, which will be less of a love letter to Warhammer and more of a lover letter to Greyhawk. I would point you to some of the changes in a blog post, but according to playtesters in Discord, a number of those blog posts are obsolete in the latest versions. The setting for SotWW is less fiery explosive diarrhea and more Gygaxian gonzo.
You may also want to look into the AGE system. It's easy to run and play. It's a 3d6 game where 1 die is a different color than the other (i.e., the Stunt die). If the PC rolls doubles on any of the two dice, the player gets Stunt points equal to the value on the Stunt die. Stunt points can let the characters do different things: e.g., double-attack, armor penetration, bonus damage, etc. There are even Magic, Social, and Exploration Stunts. There are three classes in Fantasy AGE, and it's classless in Modern AGE.