I request full autocompletion support for all attributes (especially name) in the rules channel.
Ideally, the options should be offered in relation to the context to reduce the amount of time spent with dealing which rule definition has to be made in order to validate input on a certain input component.
Example: Choosing a PROPERTY source such as an CMS_INPUT_TEXT shouldn't offer SIZE.
At least the GUI should throw an error such as appears in the log:
The element 'st_text' does not support a property named 'SIZE'!
Looking up the current options of an input component is quite annoying.