Marcusy u dun have to bang wall . instead it the others that need lesson on the proper flash exposure with ambience.
unless u can shoot at low shutter speed which is not practical especially if u shoot event. A550 or a580 will be a better choice for yr need.
for yr info ,for the sample the ceiling u had shown it doesn't matter whether u tilted yr flash at 70-90 degree..unless yr metering for the ambience lighting is at near -1 stop at least...yr flash in ttl will have to 'overwork' and still unable to fill/merge completely the ambience nicely