I think you are using all of the tools available - in RDS and in Carrara as it has no more tools. Carrara also only shows = 0.00pts - and yes 0.000pts is needed. I also have to add a "0". The way you cut your groups? 1)I would morph a point on either side - rather than add the new ones for the seam. 2)RDS will generate the duplicate verts at the seams when you turn one group into two or more. 3)You need to be very careful how you name new groups. The subtraction method works very well. Never go back for pieces. Start over instead.