Andrew

the kama is a non-kaguya descended chakra manifestation, normally the chakra in the world is from her though.

Kaguya's son distributed chakra freely among his descendants and their friends, which created the various ninja clans in the first place... Friends of friends and things obviously got out of control, probably due to not a little bit of manipulation by zetsu.

Why would they freely give out information on their home planet? If we had some benevolent person like the son of kaguya, sure, they might share information just like he shared chakra. What do you want the ninja to do? Somehow infiltrate the otsutsuki? And how are they going to do that when they know nothing about how to leave their own planet? The closest thing they have to being able to leave their planet was with the kamui dimension, which could just as easily have been a real moon or something, rather than some magical place, but who knows, really?

I think you underestimate how long they can live? We have various immortal ninja like hidan, kakuzu, orochimaru, and you think otsutsuki aren't just chilling the centuries away?

As for point 4, it could be explained i suppose if there was another show or even a book.

As for point 5, we're talking about can travel to new worlds, of course they are powerful. This isn't star trek or star wars, and 'chakra' seems to do way more than technology does in those shows and potentially more than what the force does in star wars.

I would assume that otsutsuki seek out other planets in order to fight back against other otsutsuki. IOW, it's entirely incorrect to call them a clan. They are more like the otsutsuki species. They get power by any means necessary. They're not some united species/family... It's probably a universal culture not unlike our current global culture.

They might have some leaders, but evidence does not point to unity.