Hi,
I have implemented in the same way as you in radPropertyColuna_EditorInitiaized event, i faced lot of issues with this event.
Say assign one event or max length for the property, then if u click any of the prperty , then the same business rules will apply
i mean for all the textbox editors those events/max length properties will apply However when am implemented the same functionality in the radPropertyColuna_EditorRequired event, it was working fine.