Wow, it's lovely - great design. You could raw edge applique by just straight stitching close to all the edges, that would be quicker than using buttonhole stitch, or satin stitch. If there are only a few spots coming loose, you could put tiny amounts of Elmer's School (must be school) glue behind them and ironing to heat set it. I only use fusible webs to hold things in place until I can stitch them, I would never consider this to be a final solution on its own.