Hi Malabamba
Google translate isn't perfect, so it is hard to understand exactly what your question means. Also, my knowledge of CGA is far from perfect too. But I'll do my best.
Cheers, David
(1) Is there a way to make it move, "inseparable" from the adjacent polygons?
I don't think CityEngine operates in the same way that 3d modelling packages, by stretching the connected polygons. So I would say 'no'.
(2) Is there any way to know the coordinates of the vertices of the polygon?
Surprisingly, I don't think you can get the coordinates of the vertices directly.
There are a number of functions you can perform: including geometry.Area / geometry.isRectangular / geometry.isPlanar / geometry.isConcave. These return a value, like the area, or test the shape of the geometry.
3) Can somehow get access to a variety of materials id, from imported mesh?
I think this is not possible, regrettably