Hi Haroon,
I guess you would be permitted to continue the flight up to a point of landing with enough wing tank fuel available to be legal.
Sorry, I meant landing with minimum reserve fuel in the wings.
What's the chance of damaging the structure after busting the ZFW limit
I don't know - but provided you didn't come too close to the maximum "g" published during the flight, then you should be OK. I'd guess engineering will have a method to calculate the loads at the wing / fuselage box for different wing fuel loads - but I'm only guessing.