I am an absute beginner when it comes to wool applique, so there are many questions that I cannot answer because I simply do not know the answers yet. What I do know is that quilts made with felted wool can be washed because the wool has already been shrunk through the felting process. I would also make sure to prewash the background especially if it is flannel. I think that fusing the woool applique is generally a good idea, but again, I am no expert. As for the type of needle, I use one that fits the thread, very non-technical answer, sorry. I will take all the advice I can get before I venture into any bigger, more time and money consuming projects. Thank you everybody for your input and keep it coming