And yes, as you asked about the exposure, I tried shooting it on 400 ISO in the late evening with a flash, on P mode, possibly on f8. It would surely have to extend the shutter to get enough light (if it tried to do that).
I have to ask, in P mode, it does try to reach the minimum shutter speed and if its not able to make up the exposure, does it automatically change the aperture? What is the best way to shoot with a flash? P or A mode? (sorry I have this confusion for a LONG time now)