I don't think Wonder Under is enough to guarantee a permanent stick. I actually use Heat n Bond ultra if I am not going to sew down anything appliqued. The down side of using Heat n Bond Ultra is that, if one decides after the fact, to stitch through it, it can make quite a sticky mess of the needle.
I know some people use a fine mesh over projects with many little pieces and do a meander type all over quilting.
As to the second part of your question, sorry can't help you there.