[X-FID]

I would guess any damage near the leading edge of the wing would be a major problem, even if it was 1 tile, it could cause a chain reaction IMHO. There are many others more knowledgable about the shuttle than me around here though.

[dtel]

I see what you are trying to say about the wheel well, but the sensors began failing before the wheel well.
It was one of the last sensors to go.
The heating started at the junction of the wing and fuselage,(check the press conferences for you anal geeks), this could indicate several problems including coming in off tangent.
Nobody knows yet what happened and it is way too early, to hang our hat on a cause.
It is easier, to eliminate certain causes at this point, than to pinpoint the cause.
I agree the foam is a problem, but it is a known problem that occurs every flight. This is nothing new.
Blowing up on re-entry is.