How do you remove non-App Store apps that are not in Applications from Launchpad?

Question

Hi, this is my first post to the Apple forums...
     So, I use the Steam game app a lot to manage my different games on my computer. Recently, I cleaned out the games I no longer wanted or had lost interest in, and all of their files, INCLUDING the .app files stored in Application Support, were successfully deleted. But, Steam also automatically adds app shortcuts to the Launchpad when you download a game, which is an option I always left checked during the download process- because why not, right?
     The problem is that now, even after completely deleting ALL TRACE of these apps, they remain on my Launchpad. Just keeping them there isn't a solution; as a very neat, organized person, it would annoy me to the end of time to have random apps on my Launchpad that don't do anything. And since these apps aren't from the App store, they don't have an (X) in the upper left hand corner when you hold down on them.
     I don't know tons about Macs, but after a quick scan of things online people have recommended deleting all the files for your Dock under Application Support, because apparently Launchpad is based on your dock. But that doesn't sound right to me. I thought Launchpad was based on Applications? Again, I'm more savvy with Windows but I just got this thing a year ago so I'm doing what I can.
     On a side note, these game applications were stored in a folder titled "Games", which was originally identical within both Applications and Launchpad. Once I began deleting apps from the folder in Applications, however, they got stuck in the folder within Launchpad.
     I also cannot move Game Center out of the folder in Launchpad, and when I do so it says "This app cannot be modified/deleted", even though I originally had Game Center outside of the folder.
Computer specs:
MacBook Pro 15 Inch (mid 2009)
Running OS X Yosemite (10.10.1) [I updated just last night, I had been running 10.9 before and still had this problem]
Processor: 2.8 GHz Intel Core 2 Duo
Memory: 4 GB 1067 MHz DDR3
Graphics: NVIDIA GeForce 9600M GT 512 MB

Answer 1

I found the following in the Macbook Help, and the last bullet worked for me.
"You can uninstall apps you got from the Mac App Store, from other websites, or from discs. You can’t uninstall apps that are part of OS X, such as Safari and Mail.
Apps downloaded from the Mac App Store: Click the Launchpad icon in the Dock, hold down an app’s icon until all the icons begin to jiggle, then click an app’s delete button . If you later want the app, you can reinstall it from the Mac App Store.If an icon doesn’t have a delete button, it can’t be uninstalled in Launchpad. For more information about Launchpad, see Use Launchpad to view and open apps.
Apps that have an uninstaller: In the Finder sidebar, click Applications. If an app is inside a folder, it might have an Uninstaller. Open the app’s folder. If you see Uninstall [App] or [App] Uninstaller, double-click it and follow the onscreen instructions.
Apps that don’t have an uninstaller: In the Finder sidebar, click Applications. Drag the app from the Applications folder to the Trash (located at the end of the Dock), then choose Finder > Empty Trash.If you change your mind, before emptying the Trash, select the app in the Trash, then choose File > Put Back.WARNING: When you empty the Trash, the app is permanently removed from your Mac. If you have any files that you created with the app, you may not be able to open them."