The high idle is normal. It's a 3-banger with no balancing shaft...
The no auto-stop, check the sensor that should be mounted in the front bumper, make sure the wires haven't been chopped (very common). Also: try turning the heater/AC system completely off and see if that makes it works. Also: no auto-stop unless the AC system is in ECON mode. And no auto-stop in ECON mode if outside temps are less than ~40F, only option is to turn the heat all the way off.
The exhaust leak you're hearing is probably the flex gasket on the exhaust downpipe... replace it and the springs/bolts. It's also often associated with a torn rear engine mount... check this by putting the car in gear on a flat surface and have someone rock the car back and forth while you look at the engine from underneath.
2004 Honda Civic Hybrid "Eeyore" @ 51 mpg
-MaxIMA battery from Bumblebee
-Lower grill block
RIP 2000 Insight, 40k miles @ 69.2 mpg
Last edited by samwichse; 01-22-2013 at 08:18 PM.