In the EveryStep Scripting Tool you can access the advanced settings by clicking the wrench in the upper right hand of the window.
When you change advanced settings, the change will not go into effect until you begin recording a new script.
On the Miscelaneous tab of advanced settings there are two options:
“Disable automatic launch Assert Dialog After page navigated” will stop the Keyword Validation window from automatically popping up every time you load a new URL.
“Don’t show Edit Script dialog on separate window” will disable showing of separate window when you apply any available script edit tools: