www.crowcams.com.au
I will answer your questions according to what I noticed when I went for a ride in Thanatos' car.
idle was a little lumpy, but not harsh, I reckon it makes the car sound mean, and yes, there was no problem lighting up the rears.
EA cams are easy to change, and would not take more then an hour to do.
Any mechanic will be able to install it for you, however, if you want iot fine tuned for maximum gain, then you might need to invest in a variable cam gear, and have it dyno tuned.