If I click on the button with the tooltip "ruler assistant editor tool" and click on the "plus" sign button in the "Tool Options" docker, I get what looks like the tool discussed here:

http://blog.cberger.net/2008/04/08/draw ... ant-ruler/

I can make the resulting assistant invisible by clicking on the menu item "View" -> "Show painting assistants", but I can't find a way to remove it altogether. How do I get rid of this assistant outright?

When you have the tool that creates guides selected, you should also see an icon you can drag to move each guide, and a red X icon you can click to delete it as well, just like in the image below:



If you have the tool selected and don't see these, you may have a bug to report at http://bugs.kde.org.

I can't see either a move icon or the red "X" on (what I think is) the painting assistant. If I make a perspective grid, I can see a red "X", but not a move icon.

What version of Krita are you using? For now, I'm using version 2.3.3, self-compiled on Ubuntu Lucid Lynx with the Kubuntu backports installed. (BTW, I'm thinking of moving to either Fedora 15 or Natty Narwhal. Of course, with Natty, I'd need to wait until its Qt package is fixed, but that shouldn't be long.)

These icons should show up in the assistant tool. Might be that this was introduced after 2.3.