As I mention before, to edit management pack with views created by AVE you need to download the MP file. I have been update links for download MP. Now you can always download the latest version of the AVE MP here:
At the moment with AVE you can use two different way to set criteria: by Criteria Builder (standard component of the SCSM 2012) and with XML Editor (basic text editor). The reason of using two different ways is simple: Criteria Builder allow you to add criteria fast and without knowledge of XML but is has many limitations and in some case working not as expected.
All views created inside SCSM are stored in management pack. The best practice is separate type settings (like class, relationship etc.), forms and data available in console (like lists, templates and views). But very often all that settings are saved in one management pack. And when you try to edit such management pack using Authoring Tool you can be in trouble because Authoring Tool require loaded all sealed management packs which referenced from management pack which is editing.
The good news: Advanced View Editor 2.0 for SCSM 2012 will be available at the end of this week. The bad news: will be available two different versions: free (Free Edition) and paid (Pro Edition). Get more information below.