I probably had bad breath for about two days in the entire time I did LL. The only real reason for it is dehydration so just drink plenty of water and you'll be fine.
As for excess skin, yes, you may get some depending on your age and exercise habit. I have a wrinkly tummy which nobody apart from me can see and to be honest, I quite like it. It serves to remind me how far I've come. It is much better than it was after my initial weight loss though. Given the amount you have to lose you shouldn't be too bad.
All the best with your LL journey. You'll be slim for summer!!