02 chevy silverado alarm

Well first of all unless you have a shop install it asianwolf wont warranty it.  Thats something to consider, go read his warranty policy. 

I don't know anything about your particular vehicle or alarm system so I can't answer those questions. 

As far as whether or not you should attempt it, I suppose thats up to you, only you know how much experience you have with a digital multi meter, tracking down specific wires and proper wire routing and concealing.  I have lots of 12 volt audio and video install experience and I installed my alarm a couple weeks ago and yes it was a challenge.  Theres definitely more to it than a stereo intsall.  I would say if you're not confident in your skills or if you dont understand what the install manual or people here are saying, get it professionally done.  Read and research it here, read through the install manual, understand the risk to your vehicles computer and electrical systems, and make the call.  Good luck whichever way you decide!!

if you are not goin to do a remote start you are not going to need the passlock 2

if you are going to do the power lock you will need to do the 3 wire systemand if you need wire diagram go here www.designtech-intl.com

good luck let me know what'up djram19@yahoo.com