I have just had a clifford fitted with intelliastart.
1. I have my Interior LIght on 20sec delay and its fine.... DOnt think the engineer set it up to regonise the light though, he never said anything.
2. Intelliastart doenst work on a timer, its ok when you start it up, it stays locked....
But when you want to arm it to turn off, it wont turn off untill you lock and set the alarm, so you still have to ideally stay with the vehicle. (even though any theif wouldnt be able to nick it because as soon as the break is depressed the car cuts out and the keys arnt in the ignition.
But if your happy to stay with your car for a few minutes after pulling up, then thouroughly reccomend intelliasart and for £150ish extra, it aint all bad.
"oh and yes i had to have the vecta completely disabled"