Thanks for all these changes - we really like the functionality the Live Data macro provides.

One question - for the slider icons, are they supposed to obscure the text when the mouse goes over the column or is that a bug?

These overlapping icons should not exist anymore on versions that contain this fix. However, note that this fix has only been released in XWiki 16.x and is not part of the current LTS version. There was some controversy about the appearance of the column separators which is why I found it safer to not backport this change. If everyone agrees now that the new appearance is okay, we could also discuss applying the fix to XWiki 15.10.x.