Some progress, and some frustration

I made some significant progress in Tree #1, but unfortunately I'm now pretty frustrated.

I'm quilting it with a variety of patterns, and switching up the thread color as I go along. 
Here I started with Paisley in white, and then added Cucumber vine in yellow along the edge.

I've done some feathers with metallic thread, which is working quite well.  I've tried universal needles and metallic needles, and honestly there isn't a difference for me, so in the future I'll probably stick with universal since they're cheaper.  Here's a shot of the back.

Now for the frustrating part:  I started by stabilizing the major seams by quilting straight along them, with watersoluable thread on the front and regular thread on the back.  Now as I go over these lines I'm getting some little wrinkles. Yuck!

The watersoluable thread dissolves easily, so I took out the straight line going through this feather.  It helped a little, but the wrinkle is still there.  Now I'm wondering if I should take out all of these straight-line "stabilizing" stitches before I do any more quilting.  As I did these straight lines, I took out lots of safety pins along the way, so I'm wondering what will be worse- having no stabilizing stitches and no pins in these areas, or keeping the stabilizing stitches which seem to be causing wrinkles when I quilt over them.  Any suggestions?