Thanks for the update. As far as the ~~~ goes, many machines have what we call "serpentine" stitch and it looks exactly like that and hides any number of fabric or piecing or quilting sins.
I used it recently for the first time, I should have adjusted the points so they were more curvy than pointy but I liked it on my sample and by the time I realized I didn't like it so much on the top I was already committed and decided to soldier on. Also, I didn't draw the lines I should have for the rows with the big blocks but most people aren't going to notice there is a bit of a skew and some of the grid is a bit off here and there. A lot of times we are just too close to our own work, and any flaws we are aware of are magnified.
I posted a picture of it here, I don't recommend high loft batting for beginners btw, no need to make it harder than it has to.
Quilt help needed, Soft n Crafty