Hi Piet,
do not worry about worry about posting your experiences with Groboto ... on TV, the 'next Top Model' shows have more than one model, too, don't they ,-)
What you described is just like the frustration I had half a year ago ... as I came to a point where neither inspiriation nor playing with the software gave satisfying results. But I am glad that I might be able to help you and others. In fact, I restarted GroBoto one week ago to build up nice shapes. Shapes to be modeled within sculptris. But now I am going for direct building up in Groboto ,-)
Try to build up your model as much lined up as possible. The Y-axis is the models length, the Z-axis is its depth. Anything like arms, legs tentacles should be placed along the X-axis, as you can mirror these easily. Your approach with 'Send Object Home' is most times sufficient, but I follow another way:
1. In the Object list, right click the Prim and choose from 'Place at world center' or 'Place at selection center'
2. I prefer the second one, as the new object jumps right into place where I want it.
For example, I have two parallel Cylinders ... quite long (like tubes), next to each other. And I want them to be somehow connected:
1. Drop one Cylinder at world center and scale it to your needs.
2. Shift it along the X-axis, right click it and do a 'Duplicate and mirror object'
3. Select both cylinders and place a Box-Prim into this selections center.
At this point the selections' center will be world center, but think of any situation where the pair of cylinders is way off the center ,-) Look at my model's shoulder area, how I connected the tubes in the center portion. I modeled it separately, and saved it as a Prim (Folder Primitives). Later I sent it into the scene using the 'Selection Center' thingy ,-)
What I like about Groboto to let loose from coordinates, just building up in a fluent progress. Sometimes, when building my own primes I would like to have coordinates, but. There are other ways to get perfect symmetry - but I am sometimes too lazy ,-).
By the way, I bought accidentally the windows version, while using a Mac ,-) The people at Braidart have some happy days ,-)
The admins normally react quite fast (weekdays) ... so keep on hoping! Bad thing is that you got the Mac-serial already ... you might be able to sell it on the free market, I guess.
Have fun and keep on posting ... I do not mind.
Volker
P.S.: I am going to post a small workflow later this day.