Currently, there is no "debug" connection between ETO Studio and anything other than Inventor. Getting this connection right is one of the hardest problems in supporting a debugger. However, you can use ETO Studio to edit and work with libraries that are host indepedent, and you can of course use the editor for host-dependent stuff. Since Studio runs an Intent kernel to compile source when there is no connection, you will get some of the benefits.
In addtion, Inventor now supports many of the original ISL (Intent Standard Library) primitives, so you can actually use Inventor to run rules restricted to these.