Alexander has reached the ripe old age of 8, and now he's ready to become a warrior on a Klingon ship.
Ok, I literally LOL'ed at that.
I think the thing that bothers me the most about the whole Alexander/Worf thing is that it completely contradicts the way TNG left the two. As annoying as Alexander could be, there was a progression in his relationship with Worf on TNG, culminating in "Firstborn" where Worf refused to be separated from him. Worf wasn't winning any father of the year awards yet, but he was trying.
So it was a little annoying that they just disregarded all that when Worf got the job on DS9. I get why the writers didn't have him bring Alexander to DS9- there was already a single father on the station, another one would be redundant. But the way they handled it was just bad, and "Sons and Daughters" is the pinnacle of that. It had already been addressed that Worf's parents were too old to take care of Alexander. Maybe if Worf had decided to send him to military school as he'd contemplated in "Firstborn" then him showing up on a Klingon ship would have been more believable.
And I can't believe that Worf's parents wouldn't have told him that Alexander ran off to join the military.