I had a nightmare hi idle ZForce 800, same motor configuration as the UF. It became progressively worse & was heat related. Heat is not necessarily a symptom to the same problem, it was a symptoms of the one I was working on.
If you have covered the basic's try this test. You will have remove enough of the air intake so you can have good access to Throttle Body. You need to identify the air bleed for IAC, while it is idling place your finger over the air bleed. You should be able to crudely control the idle speed & stall the motor. That will confirm you are not chasing a mechanical condition such as an air leak. As well the ECU will have the range to control the idle speed.
Let us know how this test goes.
The coolant drip sounds like the ceramic seal as NMK suggested. When the Chinese copied this motor from Can Am, they copied the problem Can Am had back around 2006. The difference between these manufactures is one will fix the problem back in 2007. The other continues on today...dripping
