[JJVIGGIANO (OP)]

Recently, scientists such as Richard Dawkins and Dan Wegner have made radical claims about religion and free will, respectively (vide "The God Delusion," http://www.hno.harvard.edu/gazette/2000/10.26/03-freewill.html [nofollow], and "The Illusion of Conscious Will"). Who should decide if and when a religious or philosophical issue becomes a scientific one?

[Bored chemist]

If a question is open to scientific study then I don't see religion having any grounds to stop it being looked at scientifically. It's not really the business of science to debar those who are religious debating anything they like.
If the question isn't one where science can offer an input the I don't see science bothering to look into it.
The point at which there's a problem is where religion and science sometimes seek to cover the same ground and religion comes to a conclusion that's not suported by evidence.

[Soul Surfer]

One of the great powers of human language is its ability to use metaphors to explain new ideas in terms of other well known facts but of course metaphors are bound to have their limits.

When people try to venture beyond the limits of day to day life and talk about the origins of life the universe and everything naturally they revert to metaphors and end up by personifying their metaphors and creating gods and religion.  This is not in itself a bad thing because it can lead to useful insight into optimum ways to behave. 

I believe that the exisence of  religions has enabled mankind to think beyond the limits of everyday life and family to form united organisation to create the complex society that we have todsy and without it we would still be in family groups hunting gathering and killing most members of our species that entered our territory.

However very often the metaphors are taken beyond their practical limits and bigoted fundamentalist ideas that do so much damage in the name of religion are caused when this happens.  it is always important to remember that when anyone claims they have the total monopoly of truth in any area they are by definition wrong.  And that includes scientists