Letters to the editor have been empirically shown to change opinions.
As to this topic, I guess my question is, what is the aim? To stimulate citizens to oppose wts ownership of property there, to get them to contact their local government to prohibit wts from buying the property? Then that's a good aim, but use a specific call to action in your letter (ie, "Call your councilperson today to tell them to vote no to wts development").
They already are against it but perhaps getting them to tell their elected officials of their opinion would affect a vote. Of course, it would need to have an appropriate reason, not anything that smells like religious prejudice.
If it's too late for that, then what's the goal at this time? To educate Warwickians to be on guard for door knocking cultists?