He does have a tendency to mix the two, and make claims that can't actually be substantiated by the scientific method without belief in realism, that is true. It doesn't stop his evolution work being excellent, it just means he pushes it a little further than it can actually go without faith. (eg, evolution implying somehow that god doesn't exist. It doesn't, at best it implies that god is unnecessary, which is a similar result but definitely different overall).
That is a problem of Dawkins' own making though, he used his scientific reputation to shoehorn his philosophical beliefs into the world, if he wants to stop being pulled up on it, perhaps he should stop doing it.
As for it being a free country, of course it is, and I fu
I think he has actually stopped doing debates with creationists and theologians! If theolgy comes into the equation on a scientific debate then he is obliged to answer!
lly support Dawkins' right to publish whatever he wants, that doesn't mean I am required to give it any more credibility or attention than work by any other religious fundamentalist.