I think the convention is to have an election pretty soon after a hung parliament in order to ensure stable government, as it's pretty easy for a weak coalition to be defeated in a vote of no confidence. I'm not an expert, so I'm probably wrong, but that's how I've understood it.
I'm a member of a British public, am I not? This is just how I see things. Of course, other individuals can speak for themselves.
No, I think you're right. Makes sense. Although they cant be so sure of winning again, so seems a bit of a risk. Depends on where the opinion polls are at the time, so a little premature for the media to be assuming there will be another election shortly. But then thats the media I suppose.