Wow, lots of advice. Looks to me like you're having the normal issues when learning FMQ. I assure you my first quilts were a lot worse. Here's my take on things.
If you notice, your quilting around the lamb is actually quite good. The backing really shows up when there are areas of the quilt that are not quilted as much as the others. So, the lamb area looks poofy on the back. When there is a poofy area, you're bound to get puckers beside it.
Spray basting or using fusible batting is a great fix. Pin basting is also very good but you have to take the time to make sure you tape the backing down tight to the table before layering the batting. Take the batting out of the package before you're ready to use it so it can relax and 'dewrinkle'. Make sure it's straight and evenly laid out before adding the top. Smooth the top from the center to the outside. Once the entire quilt sandwich is ready, pin baste from the center of the quilt to the sides, pinning every 3 or 4 inches. I even pin baste when I use a spray baste on larger quilts.
I find that the quilting works a lot better if I quilt evenly throughout an area = making the spacing between the rows of stitching about equal. I do SITD around blocks before filling them in. If you've made the backing tight enough before basting, it works.
When I'm ready to do the borders, I stitch the edge together, about 1/8" in from the outer edge. I find it helps to prevent the border from bowing out. It also helps me gauge the border design so it fits in the border but doesn't get chopped off by the binding.
Anyway, keep up with the fmq. You're doing great, you just need more practise.