How do we determine our legal risk regarding IP?

It seems that you effectively have a two-part question - 1) how do you determine if you might be infringing someone else's patent rights; and 2) how do you determine if someone is infringing your patent rights.

With respect to 1), you can have a professional patent attorney do an infringement study so as to uncover any patents that your invention may infringe based upon your disclosure of your invention and the claims of any patents in question.

With respect to 2), understand that you effectively have no real patent rights at all until your patent issues. When you have a patent application on file, and particularly after the patent application is published, you are effectively giving notice to the world that you may eventually obtain a patent and third parties should therefore be aware of the fact that their products, systems, methods may infringe your patent but your patent rights are not solidified until the patent issues. In addition, patents are often misunderstood - patents do NOT provide the patent holders with a right to manufacture their own patented invention - patents provide the patent holders to prevent others from making, using, or selling the patented invention and thereby infringing the patent.