I think it's fine as-is. I've left bigger spaces than that unquilted and it doesn't really show, especially if the quilt is going to be used rather than hung on the wall.

Nice quilt!

Yes especially since the W&N batting says every 10". IMHO that is enough quiting since you can see the pattern and the fabric and they are not overpowered by the quilting.

It might be cool to quilt vertically and horizonally through those blocks using a different color thread than you already used.

I think it isfine as it is.

Less quilting is always better for my quilts. I think that your have chosen wisely in the amount of quilting for this project.

I think it is fine as it is.

I would look at the batting instructions first and see what they say!
If your batting is Hobbs 80/20 they recommend quilting not more than 4" apart.

If you like the way it looks, stop quilting and put on the binding.

I like it the way it is. But, if you *wanted* to do more quilting, I'd suggest something swirly in the center of each block. Or you could do something swirly that encompasses both of the sashings....which would highlight the centers and make the sashings recede. Doing it that way, you could start and end at the edges of the quilt. Do it vertically and horizontally.

If you are concerned that the illustrated quilting would not be enough, you could just do it all diagonally, too.