I tried to search the forums, but it kept spitting up jibberish. Just wanted to get that out of the way for those who always like to flip out when someone brings something up that's been talked about before.

Anyway, I have an 03 element with the factory keyless and alarm, but I'd like to get a remote start kit installed. Will this mess with the honda alarm system, and will it void my warranty?

no and no. I have 2 systems, a Viper 550esp (in the car now,7 months old) and a new Viper 790xv that the girlfriend got for me. I'm having the 550 removed tomorrow and the new one put in. I love the 550 (790 just has a few more features, but also is $600 installed). The 550 can be programmed for keyless entry, alarm, remote start, etc. It's a great thing to have. I can start the car from inside the house on hot or cold days and the car is nice and comfy when I get in. The system has a bypass that allows the car to start, but the factory anti-theft to work. The system has been flawless and works from over a block and a half away near my office in the city. I recommend getting one highly!