Hi Michael, thanks for the pointers. These look actually to be what I was looking for. Great stuff. And I should have known that there is a way in MoI: This software is just brilliant (a small reflection of it's inventor, certainly ;)
And make lines or curves in a special color say "pinky" don't make the same work like construction 's lines?
You can use them like a special grid of construction, no ?
And hide them as you want ;)
You could also use your regular lines as you were, name them something like 'construct' and lock them, in that way object snap still works with them without worrying about moving or deleting them accidentally.