#1 - Two users, (1) and (2),  open the same asset. User (1) saves OK. User (2) will be prevented from saving as their view of the underlying asset is out of date.

This is how the optimistic lock pattern works. It is ideal for low con-currency usage patterns, which is how we envisage Guvnor (assets) being used.

Whether this suits your use-case is a different question entirely.

#2 - You can use the Drools Eclipse Plugin to attach to a Guvnor repository and view it's content. This is a little out dated though and some assets (in particular the web based decision table) cannot I suspect be viewed.