Don't cut. Get yourself a decent set of wire strippers and pull the coating back. A buddy who used to do alarms showed me the second best thing to soldering. You strip some coating off the wire, poke a hole into it with a pick, put the wire you are adding on through the hole, close the hole and wrap your new wire end around the closed connection. Tape and smile.
I am not a fan of splices as they cut through the wire you are tapping into and can cause issues over time.
FWIW all the connections on my Viper system are soldered.
