Apps that are considered "bloat" are of course installed to the system partition. Which is something you don't have access to. The link to the app is created for your user account during device setup. It's still available to the system. Without root access they're not permanently removed. Removing them from your user means they don't run. If there is an OS update that updates apps for feature or security reasons, they have the potential to come back. You must remove them again. It does actually save battery once they're removed. You can verify this by using debug tools to look at all running services. You also don't need this app to remove bloat. It just makes it easier for those who don't want to use ADB command line.

A majority of apps won't ruin your stability if removed. The only app I know I can't remove is My Verizon Services. If I do, I lose certain functionality. If you're unsure, look up what each app does.