Do the apps actually install in iTunes on the computer? You almost make it sound like you install the apps in iTunes on the computer and expect them to appear on the iPad automatically. It works that way if you had automatic downloads on in iTunes on the computer and in the settings on the iPad. If not, and if the apps install in iTunes on the computer, you have to sync them to the iPad.
Have you tried resetting the iPad? Not reset the settings, but reset like this.
Reset the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider if it appears on the screen - let go of the buttons. Let the iPad start up.
I assume then you were at least able to get those waiting apps on the iPad by syncing.
I have posted this boilerplate countless times in this forum and all of the suggestions have worked for others in the past at one time or another. I'm sure that you have tried most of these, but take a look anyway. Look at 1 & 3.
1. Tap the "waiting" icon and see if you can pause it. If it does pause, then tap it again and see if it will resume. If that works, repeat the same steps for each "waiting" icon.
2. Reboot the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons.
3. Make sure that you do not have a stalled download in iTunes - if you have a download in there that did not finish, complete that one first.
4. If that doesn't work - sign out of your account, restart the iPad and then sign in again.
Settings>iTunes & App Store>Apple ID. Tap your ID and sign out. Restart the iPad by holding down on the sleep button until the red slider appears and then slide to shut off. To power up hold the sleep button until the Apple logo appears and let go of the button.
Go back to Settings>iTunes & App Store>Sign in and then try to update again. Tap one waiting icon only if necessary to start the download stream.
5. You can also try deleting the waiting icons - tap and hold down on an icon until it wiggles - the tap the X on the icon to delete it. Then try to download again. Apps may also be able to be deleted in Settings>General>Usage>Storage if you cannot get the X to pop up on the icon.
6. You can try resetting all settings. Settings>General>Reset>Reset All Settings. You will have to enter all of your device settings again.... All of the settings in the settings app will have to be re-entered.
7. If all else fails, download the updates or the apps in iTunes on your computer and then sync the content to your iPad.