more regular voronoi surface, please...

Hey guys!

I'm pretty new to grasshopper and got some issues and things i need to fix:
I tried to find other threads to that topic, but none seemes to handle my problem.
Correct me if i missed the right one.

I attached the files and named everything for better overview.

I try to do a skelatal mesh, via [voronoi3d] over a curved surface. [Input geometry]

All the way till [curves#1] worked pretty nice (lofting worked out good for creating a fully connected surface including the holes, which i could edit further via catmull etc..) But just a few things bothered me:
Through the continiuos scaling all cells, larger cells shrink more than smaller ones do.
The borders between cells get quite irregular.

To change that, i tried to use [connect] for all the polylined cell borders [cull] some of them and [offsetonSrf] them by a numeric amount.
As you can see on the [#2 result], the offset tool is working fine for most of the holes.
(If the distance gets to big they cut themselfes, but thats not a big thing i hope.
I anyway want to pick smaller distances
I know the lower [loft] doesnt make much sense, but it does affect the result quite serious.. i only kept it to illustrate my goal..)

as you can guess it's these irregularity in direction of the offset (some go towards inside, some went out the cells)

SO:
how can i force the [offsetonsurf]tool to move in one direction, or how can i select and reverse wrong directional curves? may offsetting towards the center of each cell??

#3 is an additional Problem, i cant find a neat solution for:
i want to create a surface surrounding the voronoi section.
how can i pick the very outside polyline of that and create a surface (similar or parallel to the [inputgeometry]
for further surfacing i guess it needs exactly this polyline to connect outside and inside later.  but wait, i probably could change the surface to intersect with to cut cells just into the original surface (which still has that outer flat surface) but only inside that smaller inner area right?