Suzuka was one example. There have been plenty of starts where he has struggled to get away cleanly. Compare that to, say, Marcus Ericsson, who hasn't lost a position on the opening lap all year. You can't really fault the equipment because Rosberg has the same clutch and - Germany not withstanding - has been getting away just fine; if anything, his poor start in Germany galvanised Rosberg.
But you are right about one thing: his starts have been dynamite. If he loses the title, it will be because of his poor starts, so in a sense his starts have been skin to setting dynamite around his title bid and watching it collapse.