Thanks for testing the extension out for us Daryl.
I'm the engineer that worked on this extension.
The issue with the white panel in the preview area was a slip up by me in a last minute update for an issue that impacted inspecting a Validation Tooltips instance on the page. After I made that fix, I didn't check to see how initial application was impacted. I have updated the extension code to show you the preview when you open the user interface.
I have also made adjustments to the script that positions the close button, so the next beta build will include that update.
We appreciate your suggestions: the optional close button, the close button font selection as well as an optional image for closing. We'll consider these as features for the next release of the extension.
FWIW: If you want to change the font of the close button, open up: /webassist/validation_tooltips/validation_tooltips.css and modify the .WA_SpryValidationTooltip_closeValidation selector. Currently it uses monospace, but change it to whatever font family you want and you'll be set. You may want to wait on changing that style until you've applied the tooltips to all of the pages you're going to apply them to, as it's possible that that css file may get overwritten after each application. Of course, if you want to override that style and avoid any possibility of being overwritten you can add the WA_SpryValidationTooltip_closeValidation class to your own CSS file (or a style block in the page) and set the font there, just make sure that it is set in your code lower in the page code than the validation_tooltips.css file is included in your page.
Thanks again for your help in reviewing this extension.