That's probably not a good idea to try to share apps since you will have to switch ID's each time you update apps and sync apps from iTunes.
And technically - according to Apple's terms - you cannot share apps using different ID's. You can actually lock yourself out of an ID for 90 days if you switch ID's and if you associate the iPad with another ID.
The bold type is a copy and paste from the site that I referenced below.
When you turn on iTunes Match or Automatic Downloads, or when you download past purchases on an iOS device or computer, that device or computer becomes associated with your Apple ID. This article describes how to manage these associations.
http://support.apple.com/kb/ht4627