How long does it take to get good at machine quilting? Uh-oh...the usual answer! It takes as long as it takes...practice, practice and more practice, I'm afraid. I've discovered that being fearless really helps, too. I make a lot of practice squares using the same backing, batt and fabric sandwich as the quilt I'm making, and I spray-tack these to avoid the distraction of pins and thread bastings. I've drawn or traced designs and practiced sewing over the lines. Sometimes the thought that you can go crazy on these toss-away pieces is just the freedom you need to relax and enjoy free motion quilting.
Congratulations on conquering meandering and stippling, and thanks for the hints. Oh...and about those "Quilt Police"? Look 'em in the eye and tell 'em, "It's my quilt. You go make yours the way you want to!"