Classic. A no start post alarm install could be a couple of things.
1) you cut the starter wire completely and put a relay between it soyou don't grind the ignition, so that's 1.
2) you have to leave a key in the car, so that could be screwing with the ews. Find the key and remove it. Then re-sync the keys to the ews
3) on a manual, you have to bypass the clutch safety , there are a couple of ways to do this, since I don't know how it was done I can't tell you where to look but basically you jump the switch with a relay, so that may have been damaged.
At the end of the day an alarm like this is not meant to be disconnected. If it was installed well, you shouldn't be able to tell where the factory ends and the alarm begins. My first rs install took almost 12 hours (lots of customization). After I became an installer professionally, it still could take 2-3 hours.
You done ****ed up uninstalling this. You're going to have to pay someone to fix your mistake. It's too difficult to troubleshoot without seeing it.