The rich man story and a camel going throught the eye of a needle is not about money or the giving of money.  The main point is offered at the end when the disciples ask how then can a man enter heaven as it appeared to them to be impossible.  Jesus said, "through the will of God all things are possible."

You are right on the other story as that is truly the only time Jesus discusses giving to the church as it were.  The idea being, that it is not the tithing, as in 10% giving that makes one rightous, but it is to give beyond what is in excess.  It is that type of giving, relying on faith to continue that provides the a person with the type of personna that is talked about in the Bible.