I would SID around the signature; do some McTavishing or other fairly tight filler around the appliqued flowers (and might even baste in some wool bat in those sections so you could make it faux trapunto under the flowers--BTW, great job on your applique). I'd probably do continuous curves on the triangles surrounding the signatures and I like the idea of doing an echo of the applique by doing flowers/vines/leaves on the borders. Very cute quilt!