The way I think of Alonso is this: An F1 car is worth millions, if you're going to trust someone to drive it, it'll be Alonso. His greatest strengths are his reliability and consistency. Being able to understand the long game, biding his time and calculating when it's worth it to take a risk.
F1 for most drivers has been up and down, Alonso is in the lead, because there haven't really been times when he couldn't switch on the tyres, or couldn't cope with the cars behaviour. Even at the start of the season, you could see him constantly correcting and manually straightening out the bolting horse.
He's so committed to winning, even in a poorish car he'll keep on fighting for points and positions, but not overdoing it and taking too much life out of the tyres or making risky overtakes.
That's also what I mean by him maturing, he has been admitting the car is poor etc. but not acting as hotheaded as the past, not arguing with his team, I think being made number 1 really helps with all that though. It takes the pressure off, the driver doesn't need to keep looking across the garage or feel like he is auditioning.
Alonso is in the lead because he's had one DNF as opposed to multiple DNFs for the other challengers, Alonso is in the lead because he's made the most of when things went bad, unlike some of his competitors. Alonso is in the lead, because he's won three races, showing that like Kimi, has no DNFs but has been consistent like Alonso, you still NEED to win races to score the big points.
Alonso is not only driving well, arguably the best he's driven in his career, but the cards have gone his way, to the point of GAINING on the second placed challenger in Spa even though he didn't finish the race. You can't ask for more than that!
Sure, but a lot of that is down to the reliability of Ferrari this year, which takes us back to the argument that the best performing driver still needs the car to preform in, which makes F1 a team sport, but you can still haven individuals who contribute massively to the team, even if they still rely on team members helping them out.
Anyway, you described more specifically I was referring to the traits I think Alonso has shown that have lead to the specifics.
Yes Alonso has had luck, but he's also been in the position to benefit from that luck. Even at Spa, Hamilton had the wrong rear wing or some other problem, so it was Button who got pole, so the McLaren could clearly do it, in which case Hamilton would have been no-where near Grosjean at the start. And Webber had a bad race, getting overtaken by Vettel who had gone for a high downforce setup.