All the owners of bitcoins are in charge (the more you have, the bigger part ot the "company" you have).
Not quite. It's the miners, and they don't have to hold the bitcoins for long - just sell them asap for an operational profit.
Yes that is corect. But the more you have, the more power you have ( you can speculate whit the price and etc). I am not talking about 1000-10000 BTC. I am talking for people whit more then 10 000 BTC.
That will be me then! Oh wait.. I only have 0.004