I'm not going to comment on all the things you said (I'll let other people do the job) so here goes:

Yes, there might be some entities that control a huge amount of Bitcoin, but that doesn't mean they have any power over it (unlike banks). In a utopian world where Bitcoin is the primary currency, it doesn't matter that it can be used to manipulate prices because FIAT currencies will be secondary. But even then, the market will sort itself out.

It also doesn't matter how much people can afford because Bitcoin's supply is fixed, so it's a given that the price will surge. They can just deal with fractions of it and more fractions can be added in the future through easy protocol upgrades should it be deemed necessary.

BTC isn't just the first cryptocurrency. It's also the most time-tested & secure (by hashrate) decentralized network. It can surpass other coins which are better right now through protocol upgrades. But the problem is that there is a lot of division due to the large number of people involved with it. It's easier to make changes to Monero for example, which has a much smaller community. It has gone through several hard forks already.