What do you mean age should be considered in regards to Kobe? Neither is in their prime and Harden's athleticism benefits him as much as Kobe's experience does(lol no it doesn't but yeah).
Dwight has always been a 20 PPG scorer, if he wasn't such a shit free throw shooter he would actually be pretty great on offense.
Westbrook is probably the best defensive point guard in the league, which is saying a lot considering how many great point guards there are in the league right now. He's ability to score is great as well, not to mention he's shown he can be a playmaker this year and two years ago.
You would take Harden over Melo? It is rather close I suppose, but I'd still take Melo as the better scorer for now. Melo is in his prime though while Harden is only 23.
can we just praise Presti for a second? He's DRAFTED three of the top 10 players in the league. that's ridiculous.