I think you points are great!!
Often times I will pin the row together and then baste the points where the seams meet and take a look at it. It it's off I can quickly remove the basting threads and try again. Once it looks good I can stich the entire row. When you have a lot of seams coming together in one spot it's hard to get things right with all those "ridges" there.
I find my main problem is that my cutting isn't always perfect; it it were things would line up more more precisely. But hard as I try my cutting never comes out perfect (or even close enough so that things line up as they should).