Thing is, the Jounins already observed that typical Genins shouldn't be able to perform even basic jutsus like Sasuke's fireball. This, again, serves to illustrate that there isn't really a set power that each rank has.
I think this only shows that Sasuke has an extraordinary amount of chakara(though I wouldn't call that fireball technique a basic one).

No kidding, buddy, that's kinda my point. The top Genins we see aren't that far from the Jounins in combat ability. However, unlike what you and others have said/implied, that does not mean they should be promoted.
However, if it were not for the Hokage's death some of these Genin's might be chuunin ATM so thats what they should be viewed as?

Let's see. Sasuke's cut a friggin' transforming Gaara in half.
I'll have to watch the episodes again but I don't remember it however I remember Naruto finishing Gaara and usualy getting cut in half means death but again, I'll have to watch the episodes again.

Kakashi killed an already beaten and weakened Haku. Which has the better showing?
How does this in anyway compare Sasuke and Kakshi's chakara / strength of the technique? You can't use the automatic assumption that just because he killed Haku(which I got the feeling that he didn't want to and was trying to stop) and not some demon that his is a zillion times weaker than Sasuke's (that was a parody on your text if you didn't catch it...)

Similarly, Naruto's Gamabunta summon is something that only the Fourth Hokage has done previously.
Jiraiya talks about how he has a hard time controling Gamabunta when Naruto him summons the first time so I would only assume that he has done so before as well.