This could be due to:
1. Incorrect TOW calculation
2.Cargo not properly latched and secured.
3.Cargo themselves not properly calculated
AFAIK, the 345 doesn't have tail strike protection. And as for the smoke, my guess is that it could have punctured the pressurised area of the fuselage causing the burning smoke of the fuselage to be circulated in the cabin. Whatever it is, it is gonna cost alot of $$$ to be repair that.
Take a look at this for full r/way usage for t/o:
YouTube - China Airlines 737-800 nearly overshoots runway at takeoff