I'll save you the trouble. A spanking means nothing to an abused child accept that all adults are untrust worthy and eventually beat their kids. Don't let anyone talk you into doing this. I know it's tempting when nothing else seems to be working.
Did you receive any training in attachment parenting? It would be helpful to find a therapist trained in attachment disorder and foster/adopt children. You sould be involved in the therapy.
Be very clear about the rules. Change the consequences to maintain control. Check out
www.nancythomasparenting.org and
www.radzebra.org. Do not finalize until you have all needed services in place and future needs written into your subsidy agreement. I would recommend reading Parenting with Love and Logic and Nancy Thomas' When Love is not Enough. There are many other helpful resources, but I'd recommend those for starters.
Be careful how you react to the negative behavior. If she knows it bothers you, she'll continue to do it. She is fighting for control because she feels out of control. Allowing her control only makes her feel unsafe. She needs two united strong parents who are strong enough to love her through her anger and pain. She doesn't yet trust you to do that.
It's very common for kids in this situation to intentionally destroy clothes. You can allow her to wear them that way, use hand me downs, garage sale or thrift store clothes, or have her do chores to earn money to replace the clothing herself. Also, remember kids do play on their knees and do odd things with shoes, so some wear is more normal than some would think.
Keep a log of behaviors and situations that occur so when she lies about you, you have some evidence of her behavior. Do you have access to speak to former foster parents? do you have copies of her paperwork that might show you a pattern of behavior? This might help you find the right kid of help. Good luck and keep posting.