hey, you can merge the verts anywhere. Just go into edit polygons > merge verts option box), thenput the number up.
As for snapping down the middle, select the object or vert you want to snap, with your move tool selected press cntrl + x, to snap to the middle, and cntrl + v to snap to verts
Good Luck.
those who succeed are only the failures that never gave up.
https://www.vimeo.com/7080130