Hey, I have a few questions...

When will tangent arcs and parallel/perpendicular guides appear, and when will they not? I often fiddle with a line to get a pink or light blue guide to appear, but my success, like my techniques, is random. I'm imagining it has a lot to do with a line's boldness.

I'm also trying to apply geometry from a flat surface to a curved surface, and it's reminding me of problems I had when I started using sketchup about a year ago: how to draw on a curved surface. This is an example of what I'm talking about:

I've tried using the sandbox drape tool, but it doesn't seem to apply to what I'm doing. Any suggestions? I can post pictures of what I'm attempting if that isn't very clear.

And one final question: is there a way to flatten a curved surface? Stretch it out somehow? I suppose that's the inverse of a flat object flown onto a curved surface, so this may have the same answer as my second question.