Hello Jason,
Straight to your questions
1. There is no limit
2. How will you reach level 3 and 4 if level 1 and 2 are not expandable?
Generally speaking, you can subscribe to the
OnClientNodeExpanding event, check the level of the node (
node.get_level()) and cancel the event if you wish to stop the expanding.
Best wishes,
Veselin Vasilev
the Telerik team