4th level play by post, two DMs, three parties, and the DMs have plans to take this into high levels (from comments, I recognize that we'll eventually be dealing with Kyuss...)
The most important house rules, from a character building perspective, are:
1) Additional bonus feat at every level (!)
2) Heavy doses of wild magic, both arcane and divine, discouraging spellcasters
3) No ToB, no psionics - more for flavor than balance concerns, I believe
4) No homebrew, but nearly all official sources are valid, including web enhancement and Dragon magazine (with permission), and a few third party are allowed
The rest of my party is a Knight/Fighter, a Bard/Rogue, some kind of fightan man who I don't have a build on, and a Cleric/Divine Mind (secretly the co-DM's PC, intended to serve a healing role). I'm an Incarnate/Factotum, currently invested in tripping (secondary tank, secondary damage dealer) and Handle Animal (I have a Warbeast Riding Dog and permission to apply Wild Cohort to it), and have already agreed with the two DMs that Cunning Surge was intended to be 1/round.
My issue is that, as the classes quickly show, the optimization level is pretty low. The Cleric/Divine Mind has a lot of potential power but is a dedicated healer, and the other three are all mechanically unimpressive. I'm a pretty good optimizer and statted my character out before I learned just how mechanically weak the rest of the party is, and so I toned things down a little (put off Wild Cohort, delayed Shape Soulmeld: Reaping Gauntlets, sword and board instead of a ranseur, etc.) but I'd like ideas for creative ways to make the rest of the party shine brighter.
Neither DM seems to be much of an optimizer, so I'd rather avoid shocking them with just how strong some combos can be. I'd much prefer to avoid prestige classes for now, and I'm less worried about making sure the rest of the party can shine at higher levels, so any suggestions that focus more on the 5-9 range are most appreciated.
Build notes: My feats are Combat Expertise, Improved Trip, Azure Expertise, Knowledge Devotion, and 3x Font of Inspiration (though note no Cunning Surge mega-novas), 18 Int and other stats all low-positive modifiers (+1s and +2s), Azurin race. I'm committed to my riding dog long-term for RP reasons, but don't want to optimize her too heavily (she's already a Warbeast and will have Wild Cohort later.)