Installing (and uninstalling) and SDK would have no impact on other apps. You cannot really "incorrectly" uninstall an app short of randomly deleting its files or something.
If you can be more specific about what errors you're seeing, what apps are not working, etc then we can probably more easily help you.
Yes you could reinstall the SDK but then if you uninstall it again you'll be in the same state you were when you did that before so I wouldn't expect anything to change. The most the uninstaller might have left lying around is adjustments to your PATH environment variable which you can just clean up yourself instead of running the uninstaller.