The only caution that I would give you about adding a lax board is that the lacrosse community is a pretty well established, and large tribe that already has a number of web discussion opportunities. But one specfic to DIII may be good.
Good points, Joe, especially the one I highlighted.
One possible additional caveat: D3 varsity
lacrosse is pretty much limited to an area from Ohio to New England and to the southeastern states. Thus, there may not be much national interest in D3LAX.com.
On the other hand, at the club
level, it's played by a number of MIAC venues. In Texas, there's a club league, a mixture of D3 and D1 institutions. I believe there's also something similar in California.
Overall, the sport is burgeoning at all levels. It's not as expensive as football,* nor do players have to be behemoths to compete well.
* E.g., in the MAC, a number of non-football members have taken it up in recent years: Messiah, Elizabethtown, DeSales.