Is there a way to make it so that when I run a Setup and my app is already
installed on the system, it doesn't prompt you for "repair" or "remove"? I
would just like for it to automatically uninstall the app and then
re-install it afterwards. How can I do this?

I'm assuming you're using windows installer to deploy your app using a
deployment project in VS.NET.

If so, you will need to change the Version property of the deployment
project of your app. This will automatically update your ProductCode
and PackageCode GUIDs. (A messagebox will prompt you to confirm within
the VS.NET IDE)

Then set the RemovePreviousBersions to 'True' under the properties of
your deployment project. Rebuild the project. Your setup will now
remove any previous versions at install time.