Hi Yanik, re: offset problem - I think the problem is that Offset in MoI is focused on working on a closed loop, not a branching structure like you have here.

It will try to join together segments that touch to try and make a closed loop but that is not good for your branching structure.

I don't think that MoI's offset will produce the kind of result you're looking for here, you've got not just branching but some pieces touching others in spots other than endpoints making "T" junctures. MoI's curve offset is not set up to handle those either.

Maybe a 2D CAD program that has an architectural type "wall" offset might do what you are looking for.

- Michael