I agree with this assessment. As soon as he's under performance pressure, he falters. He's doing really well with Force India and kudos for coming up with enough motivation to do so.
Potential is nothing if you don't use it. A large part of sport (and other things in life) is your mental strength. Although I don't agree with you on Massa, I certainly do about Fisichella. He's a clown too. 
I hope you'll have to eat your words about Massa one of these days 
If he wins the title it will be down to Raikkonen falling asleep or into a drunken stupor and the class of the Ferrari's cars rather than an abundance of skill on his part.
Well, look at it this way. He won three races last year, two in 2006 and already has one this year. He might have his moments, but the man has proved that he can race with and subsequently beat the likes of Schumacher, Raikkonen, Alonso and Hamilton, so I'd hardly say that constitutes being branded a clown. He's a good driver, he just has a tendancy to let things get to him at times. I've seen better drivers, I've seen worse drivers and the worse drivers are by far the bigger party.
In addition, unlike the majority of drivers, he's completely honest about things. He doesn't try to blame his poor performances on the car when he has made a mistake, he just owns up to it. It's a respectable quality and it makes a change from hearing things like "the car wasn't so good" or "the team need to improve" when the reality is that the driver cocked his race up.
He won three races when Raikkonen went into his not-uncommon hibernation mode last season, two races when Schumacher was struggling (and when Ferrari allowed him, it has to be said, to be fair) in 2006, and although he may have won a Grand Prix this season, it far outweighs the laughathon of mistakes he's made. In truth, I am disgusted at the current generation of drivers and their perpetual gurning about a lack of traction control. Try driving twenty years ago in cars with 1500 hp, turbo lag, no semi-automatic gears, no power steering, and little in the way of safety standards. I've seen Massa spin more cars this season than what used to happen in a whole season the 1980s! Massa's overtaking ability is also pathetic for a front-running driver. Yes, it's tough to overtake in the sport now, but, even so, quality drivers have still managed to pull off some good moves, Alonso, Kovalainen, Hamilton and Schumacher immediately come to mind. Massa: he just goes light in qualifying, leads the Grand Prix from the front, being able to achieve success because of the quality of the Ferrari and because the cars are so easy to drive nowadays. In the '80s, little things such as gear changes counted for a hell of a lot more, so Massa wouldn't got away with what he's doing now. Another thing about him is his inability to adapt to various circuits. All drivers have circuits they dislike, but they are at least always able to put in credible performances around them - you would hardly think Ayrton Senna hated Donington, would you? Massa shows up only for Bahrain or Turkey. How has he also been doing against a wide-awake Raikkonen? Not too well it has to be said. If Raikkonen finally has turned a corner and pays attention for all of a season, Ferrari will have the
de facto one-two system they were after.

Ayrton Senna: WDC 1988,
1989, 1990, 1991
McLaren: WCC 1974, 1984, 1985, 1988, 1989, 1990, 1991, 1998,
1999, 2007McLaren: WDC 1974, 1976, 1984, 1985, 1986, 1988, 1989, 1990, 1991, 1998, 1999, 2008