Whatever the camel and needle were, it's still obvious and accepted as meaning an impossibility
As to the rich man:
If you read the whole chapter, the man asks how to achieve perfection and Jesus says to lay down your wealth and then follow me - by this he means it is easy to behave in a "Christian" fashion eg give time to prayer, and be generous with your money time and effort to others when you have all your own needs met. It is the real test of a person's faith and good nature to be pleasant, generous, helpful and moreover thank God for their life when they are in dire straits. Job being the example of one who did. (Poor s0d)
So being rich in itself shows that you probably have not proven yourself truly faithful.