Depending on the circumstances, hiring your own lawyer for the read might be a good idea once a sufficient contract is in hand. You can do all this, and still not be bulletproof. But that's the nature of the country these days. Beyond any legalities, I would absolutely expect to have some flak coming back my way. Then again, that can be some of the most fun.
Clarification is in order.
Slander is the oral equivalent of libel. Libel is in no way minimized by the absence of accompanying slander. If what you write is the truth, then it's the truth. Dick, be true to yourself, your subject, and your readers. Besides, I'll never speak to you again if you compromise your principles.