I love working with wool, my favorite quilts to make :)
i use a slightly wider seam allowance than 1/4", but probably not quite 1/2", press seams open on the heavier fabrics, to one side it they are thin, and go that way ok...i tried fusable once for my appliques...did not like the results at all, it was hard to work with and hard to stitch through...now i just use freezer paper templates and if i need to hold an applique in place while sewing it down i use pins, but usually i just hold it with my fingers if it's a small piece, pins for large ones. make sure you wash all of your wools before beginning, as long as you wash them in hot water, rinse in cold, then dry in hot dryer your wool will not fray when you are hand stitching it. my last big wool quilt i used an awesome double sided heavy flannel from benartex for the backing and a wool batting...it is SOFT, FLUFFY, OH SO WARM, AND just an awesome quilt!!! the one i'm working on now is more crazy quilt style with embroidered blocks, appliques, what ever...it's gonna be great! if you visit the web site for the cotton patch quilt shoppe (in East Tawas, Michigan) one of the links is for customer show and tell...my black wool quilt is the one she shows on the link :)
jump right in, once you start working with wool you will find you want to use it more and more...at least i did.
good luck.