First of all, thanks to all of you who helped me in this process, who gave me feedback, who answer my questions, and so on. I'm really happy to be a part of the GSoC program, it's a great opportunity for me, and I'm glad I'm doing it with the help of this wonderful community.
Well, it's time to work now :)
As Yoshiki suggested I made DataGraphMorph a kind of PasteUpMorph to allow the vectors and points to draw pen trace. But I ran into some problems.
The main problem I have is that when I move across the plane the turtleTrailsForm doesn't update correctly. It also doesn't allow drawing beyond the extent of the morph. If I want to make the illusion of an infinite plane, the current implementation of the turtle trails should be modified (at least for my morph).
What do you think?