Gday. Just wondering why more then one vertex is selected when I click on a single one along the edge. This also happens once its mirrored, making manually aligning the vertices a pain.

Hey Marek, good question! Since that vertex is along a seam, both of the ones you see selected in the UV view are that one vertex - it needs to be in two places at once in UV space in order for it to split. If the selection is annoying (as it often is when moving islands around), you can turn off Selection Sync in the UV editor header. 

Hope that helps!