Taking an SEO hit to change the name is a business decision that only you can make. Just compare the advantages and disadvantages of keeping the name vs. change it, and project out 1, 2 and 5 years with your best guess about how things will go.
As for the LLC, that is pretty easy to do. However, be sure that you need an LLC before you bother with it. Like kish said, you can insure yourself for liability if that is your only concern. An LLC is useful for both liability purposes and for taxation.
So, you need to ask yourself: how much liability to do you need? some people don't really need any. And, are you earning enough to make the LLC worth it? If you are doing $1000/month an LLC may not help you and could actually cost you some. But, every situation is different.
Creating an LLC is easy, just make sure you know what you are doing with taxes or have good advice.