Powerwashing???
#3
I was told its okay to do so, but I wouldnt just cause I feel like it wouldnt be safe. I was told though, you either need to have the engine cold,not cool, or you need to leave the engine running. But like said above, dont get the alt, and make sure you dont get the air filter wet.
#4
I use spray on stuff then just rinse it but it builds up over time so I might stop for now. Just makes sure you aren't to aggressive on it, like enough to knock wires loose. Id be very careful around the alt and the PCM for sure. Air filter if you have a CAI too.