Why will some apps not download , they are greyed out for some reason?

Where are the apps greyed out? On the iPad or in iTunes on your computer?

And when use the term download, to me that means download from the cloud. When you say sync, that means that you are trying to ranger the apps from iTunes on your computer. So that I can fully inderstand, which way are you trying to get the apps onto your iPad?

Try 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 - let go of the buttons. (This is equivalent to rebooting your computer.)

 Cheers, Tom 😉

Now you've confused with "they remain in the upgrades" remark. Are the apps are greyed out with the "waiting" icon under them or were you trying to upgrade them and the icons just turned grey?

Ok. Now I understand what you're saying. You don't have any restrictions set that would prevent you from syncing the apps do you? It would have to be restrictions in Allowed Content in the Restrictions settings that you would have to check.

Settings>General>Restrictions>Allowd Content.

Excellent. Glad to hear that you got the issue resolved.