I think you should decide on washing or not washing based on who the quilt is going to and how it will be handled.
If I plan on using fusible interfacing on it, then I wash without fabric softener and dry without a dryer sheet so the fusible will fuse. I had to learn this the hard way!
About the wrinkles, a friend of mine who used to work in the fabric industry, told me to spray the fabric with a mixture of water and white vinegar before ironing. The smell dissipates after a while. It really does work. Especially on those fold lines when it's been on the bolt.
Oh yeah, I always wash flannel before using it, sometimes more than once - that stuff really shrinks but feels so soft afterwards.
Don't feel like you have to justify your method - when all is said and done - it's your quilt - you're the boss. And if you make a mistake, carefully make another like it and say it was intentional - I believe I got that bit of wisdom from Liz Porter!