First thing I 'd like to say is WELCOME I know you'll like it here plenty of ideas and help.
I have used the stich witchery a few time. With this you don't have the web behide your applique. It melts and bond the fabric. I agree with the others about stiching the applique if it is going on a quilt to be used.
I'm lazy and cheap I use a kids washable glue stick with my appliques. I run a strip down the center then place and satin stich. The nice part about glue stick is if I place wrong or don't like how it look I can move it.
The other way with the fusbile web once heated in place thats it.
Good luck on whichever way you decide. Hope to see it posted when your done