If I remove the Catalytic Converter from my 2010 SE Street Glide, does anyone know if it will it void my warranty?
Removing the catalytic converter on your Harley is no different than removing a catalytic converter on your car. It voids the emissions warranty and it makes the vehicle illegal to operate on public roads. As to what would happen to your regular warranty, that would depend on what parts failed. Something like a defective ignition switch or other non-related part should still be covered. However, some dealers and companies take a hard line and refuse to work on an illegally modified vehicle. They do not want to be held accountable.
Now, in the real world it is highly unlikely you will have an issue. Unlike an automobile, where anyone can stick their head under the car and see the cat(s), your's is hidden inside the head pipe. To determine if it is still there would require someone to remove the muffler and look up the pipe. It would also require the person working on the bike to know the cat was supposed to be there. Based on conversations I've overheard, and posts here on the site, I don't think the typical dealership tech knows what bikes have them and what bikes don't.
Final word: It's your bike, do what you want. The odds of you ever getting nailed are slim to none, unless you live somewhere where they enact tailpipe emissions checks. In that case, you would have to buy a new head pipe and put the ECM back to stock. NBD
Jerry