Suggest to me a good 12th level feat?

[Nettlekid]

I'm in a sort of evil campaign that is heavily homebrewed, and partially based off of the show Supernatural. There are a lot of heavy hitters in the party, but I'm a super-rogue that never fights and can't do damage, but enjoys sneaking off to gather information or speak with allies or enemies in private. We're just about to hit 12th level, so suggestions for feats (and in fact level in general) would be appreciated.

My build so far, composed almost entirely of dips, is:
Changeling Rogue 1 (For the high skills and ability to Take 10)
Factotum 5 (The staple of the build, scattered around for better skill purchasing)
Marshal 1 (To add Dex, Int, and Cha to Dex skills, and get a free Skill Focus)
Mindbender 1 (That Telepathy and Mindsight has saved the day so often)
Warblade 1 (To pick up Iron Heart Surge and White Raven Tactics for the party)
Shadowdancer 1 (Hide In Plain Sight is wonderful)
Exemplar 1 (For a couple of bonuses and all those lovely Take 10s)

My feats so far are Dodge, Mobility (for Shadowdancer), Mindsight, Darkstalker, and that free Skill Focus (Diplomacy).

For 12th level I was debating between Swordsage for basically at will teleports, Shaper Psion for Minor Creation abuse, but I think I'm going to go with Cloistered Cleric, trading in Trickery and Animal Domains for their respective Devotion feats. That Trickery Devotion in particular is exactly what my character would love, and the versatility granted by Animal Devotion is fun to think about, especially since 12th level is a point where a lot of the "add X for every Y levels you have" stuff kicks in.
But I don't have a feat that really calls out to me yet, and I'm not devoted (aha) to Cleric if someone has a better suggestion.

[SowZ]

A really good feat for a build that only dips rogue is Craven. If you don't know of the feat, (it is likely you do, but just in case...) Basically, you add your character level, (not rogue level,) to SA damage. You still won't be the parties main damage dealer, but now you can at least hold your own. Even if you only have one sneak attack die at level 20, you are still average 23.5 bonus damage per sneak attack.

[Demidos]

Depending on how high your level of optimization is here, an Item familiar sounds like it could fit your bill. Alternatively, if its REALLY high op, Absorb familiar with the aforementioned feat would work.

Edit: http://dndtools.eu/feats/complete-scoundrel--60/savvy-rogue--2518/ Alternatively, this sounds like it could work, assuming your DM okay's the Skill Mastery source (it makes sense).

[Nettlekid]

Craven is appealing for anything Rogue-like, but not great for me mainly because even if I could do a small amount of damage, my attack rolls are really low. The other party members have damage covered, and my character is the type who doesn't like to get his hands dirty anyway.

Item Familiar is well known to be powerful, so I think my DM would be a little worried about it (someone in the group is known for breaking things with an Incantatrix and Item Familiar, so yeah). Also, you have to spend 3 skill points to get a +1 return on skills, right? That's good for boosting one skill through the roof, but not so good for someone like me who wants to be a jack-of-all-trades.

Perhaps a tactical feat with various uses? I was looking at Combat Panache, although my Intimidate isn't that high and I don't really want to take any damage at all. If I had +6 BAB I might take Elusive Target, but I don't. Something in that vein of trickery, deception, and mischievousness.

[TopCheese]

Go Swordsage and pick the feat that gives you Dex to damage while in a shadow blade stance. You sound like a dex build so I'm guessing you have weapon finesse... This will give you more uses for dex and help with damage, I would take craven next.

There is a stance that gives you moah sneak attack and one that gives you concealment... very sneaky discipline that one is.