I've never made a character that focuses on summons and it could be fun, but with 7 players I'm afraid I'd slow things down, even if I was always as prepared as I could be.
Eldritch Archers are cool, but you've got a point about them playing similar to my Inquisitor. I am very tempted to do a thrown weapon magus, though... Magus are cool, I just need to find a way around thrown ammunition destroying itself after it's used. On a similar vein, I've never done a Warlock Vigilante before.
Kineticists and I don't really mesh, unfortunately - every time I start making one, I get sidetracked into doing something else that fulfills my personal goals better.
I really like shuriken ninjas, but unfortunately I've never been able to put one together that satisfies me. It hasn't been for lack of trying, though! Part of it comes back to the whole disposable ammunition thing I mentioned with the magus. In addition I'm wary of relying on Invisibility for my main shtick because it's so easy to counter, considering the enemies we've been fighting are intelligent and have used scrying in the past.
So far I'm most tempted by an alchemist, an overwatch-style fighter, a thrown-weapon magus, or warlock vigilante... 2/3rds casters are addicting in their utility and versatility (alchemists aren't 2/3ds, but they use extracts which have similar application in this context).