Define nothing to do. If he's got a problem he's thinking about or he's stargazing, he can sit there for hours - but if he's just literally just sitting there he'd get fidgety so fast.
He was willing to potentially put his, and Gen's lives on the line for that lie to save everyone else. It didn't come to that, but that's definitely a rare case of Senku's ability to deceive (with Gen's help)
The pursuit of knowledge - and the fact he has not yet saved all seven billion people. He's maybe at 4.5 billion, but that's just an estimate. They're not clear about that.
You know, I'm not sure he has a favourite. He's enjoyed a great deal of options from a car, a hot air balloon, an airplane, a ship, a motorcycle, a motorboat, a spaceship...
Senku never thought much about children, he never considered he would be good with them and because he's never really been interested in the process of making them, it probably was never on his radar.
Not at all. Senku's place in his story is very established and relevent, even if for a period of time he's a bit...superfluous, but canonically he carved out his own place going forward and that's basically him in a nutshell
There's a lot of aspects that you can infer about Senku, through analysis that come into play - but his story is not about any of them. His story at its core is about this guy who is insatiable for knowledge about the world around him.
He's a certifiable genius with an eidetic memory - and he doesn't consider that to be at all important. His memory is a party trick at best, and he thinks he's just an idiot who wants to know more and more.
But yeah, I didn't have trouble with any of that, so when I play him I might hint at this or that, like the story might, but that's not what his RP story is going to be about most of the time either.
also according to the author the only person he seems to be compatible with is Gen so you know make of that what you will