What a beautiful quilt!!
I would follow the triangles, quilting in about 1/4 inch from the seam lines. Makes for a no mark quilt pattern and in the end really shows off the piecing..
I always spray baste, and have hand quilted many quilts with no problem.. I quilt on a hoop in my lap. I generally use Warm & Natural or Warm & White batting and don't feel any drag at all on the needle.. also I don't bother pin basting, the spray baste holds just fine until I'm done (which can be quite awhile) It's a great time of year for hand quilting!!