For Michael, (edit: not seen the previous 2 messages)
Yes I fully understand that, but before using the click'n'drag I was using simples lines and duplicates or move or mirror very fast.
And I still use them because I want permanent constructions lines that I can put in a style and show/hide them and lock them.
I already model pretty fast, modelling faster would create problems and errors from my side.
Instead of an Icon maybe a shortcut would do it? Like key+click

Or to get back to the original request (line from center) why not have a key to press while drawing a line to enable symettry, or a check box like make copy in the rotation tool? That would resolve many problems.

By the way keep the click'n'drag help lines they are cool, but I miss regular lines that are physically there and that react like normal lines.
If we look at the UI there's plenty of drawing tools that start from the center point, why not having a line? Its the less cluttered drop menu of all the 2d tools.

What im trying to say is that I worked for a long time without using the help lines in MoI but using traditionnal paper drawing techniques, all the people have different workflows for sure, what would be very different between help lines and lines from center point is that you would be able to change the angle and see the preview result in real time, for drafting or designing its very usefull.

Again im just a customer, MoI is already the best in his category and price range, Rhino is slow, T-splines are buggy, Maya nurbs are ugly like the maya interface, Catia is too much to pay as Alias studio as Solidworks. So even If I had money I'll go for MoI, I even use MoI instead of illustrator for doing techy drawings. Where I work a lot of people are impressed by MoI already :) But they dont do Nurbs :(

The whole problem is that MoI is already very stuffed, you can already do all the basic things and more complex things (still miss t-splines :P), its gonna be hard to keep the simplicity of the UI and the simplicity of the tools. But maybe in the futur if MoI have a liquid UI where you can drag'n'drop icons, people would make their own interface so having more and more tools will not be a real problem.