can an iPad be linked to two different iTunes accounts?
Yes you can. Just go to :

Settings > iTunes &amp; App Store 

Then log out and log in with your Id and you can redownload all the stuff your purchased thanks to iCloud. His data will be unaffected and remain on the device. 

Alternatively you can turn on Family Sharing which does the same thing but a little more user friendly by going to :

Settings > iCloud > Set Up Family Sharing.