Anything is acceptable. Your Book of Shadows is your personal item. Some of mine are in $1.00 journals, that does not detract from the information they hold. I even have a few that are plain note books.
Your Book of Shadows(BoS) should be what ever works best for you. My coven's BoS is not the prettiest but a very functional three ring binder. My personal one is just a pretty journal I choice for personal reasons.
If anyone tells you it is flat out wrong needs to give worthwhile reasons and then back out of your business. Wicca is more a personal path than a list of rules that everyone must follow exactly to avoid punishment. Use what works for you, if it doesn't, try something else.
living, please don't preach to us. it's not your job. You believe as you do, we believe as we do. You're being disrespectful and rude. Now butt out.
As for the book, it's up to you. Whatever you use should come from the heart. Besides, the animal is already dead and it's skin has already been used, so at least it's being used for something good.
Of course. My first one was a plastic ring binder, then I moved up to one of those manufactured a4 ones from amazon. I now have one from WNW.witchesmoon.net, and I love it, but I also have little notebooks I carry around with me, with correspondences, Gods and Goddesses and other stuff.
Use whatever you want. What your BOS looks like has absolutely nothing to do with it. I've used just regular spiral notebooks. It's basically for information, a journal. So whatever works for you.