Sorry, I don't know about the sewing part but wanted to say how wonderful your quilt is! Lovely use of colors!

I use Robbi's (second method listed) method. I prefer to use dental floss instead of thread and I also use a big needle. So much easier for me.

http://artwithaneedle.blogspot.com/2...read-ends.html

I would never do all that starting and stopping. It would take forever and lots of extra work. Have you considered using a variagated thread with those colors? There are lots to choose from.

Since your beautiful quilt is a rainbow of colors, why not use variegated thread and do the whole quilt rather than square by square?

I like your idea of using dental floss!

Lovely quilt. I say go for it. Pull your threads to the top, tie a knot and bury your threads, it will be a lot of work, but I am sure that you will be happy you took the extra time, where it is what you want. Good luck

Variegated thread in a color way that blends with your values would be nice.

I don't lock my stitches. I stop stitching and leave long tails which I then tie off by hand and useing a large eye needle run the thread ends through the batting and out and clip off. I feel it is more secure that way and there are no little stubs of thread anywhere. Is it a lot of work? Yes, but I like the results so it is worth it.
I usually quilt with a neutral thread so less changing is required. That's a lot of threading your machine and changing you bobbin. You might also want to consider a varigated thread to compliment those colors.