I just started playing this and I have no clue what to do! Having fun so far as a strider or ranger I believe and I just escorted the Hydra's head to Gran Soren. Bit overwhelmed but still it's a fun game.
My friend and I both suffer from this and have decided to shelve Trenched until it gets fixed, personally no big deal because I have other stuff to play. Hopefully the fix is sooner rather than later and can fix this issue as the game looks and runs great (when you aren't picking up scrap).
Its not capped at 30 fps, while you on the ship yes, but not in game. I have it running 60 fps while there is gameplay, but it drops back to 30 for the cut scenes and as mentioned before while your on the deck.
From the official IB Support FAQ on the double fine forums:
Iron Brigade PC is locked to a max of 30 fps. This makes me very angry. What can I do about it?
As of this writing, Iron Brigade PC is a faithful port of the console version and is capped to 30 fps. There is no way to work around this setting, but Double Fine is trying to find the time to modify our engine to support uncapped rendering. If and when we do this, it will be made available on all Buddha engine games (Stacking, CQ, etc).
So unless you have some magically different version of the game you are running at 30 fps like everyone else. It's not a big deal game is fine either way just getting the facts straight.