First: Although I understand the point of what you are saying regarding polygamy, I believe you are incorrect. It is only polygamy if the first and foremost commitment is to an individual church rather than to God. I am committed to my faith/church and you all are committed to the Catholic Church. But this commitment is not above my commitment to God. God is the same regardless of whether a person is standing in a Catholic or Lutheran church. I am not “cheating” on God when I attend Catholic mass. Neither would any of you be “cheating” on God if you were to attend a Lutheran service. Now, if the commitment is primarily to the Catholic Church, then the polygamy argument is more correct. This is where I have problems with the Catholic faith. But, I guess that is neither here nor there in this disucssion.

Second: The post from Weather essentially demonstrates why I cannot in good concience raise my children in only the Catholic Church. Although I am clearly not an authority in the Catholic faith, I have strong reservations about the website you are using as an instructive reference. This website explicity denies much of Vatican II, most especially the ecumenical teachings. If, truly as Catholics, you believe in the authority of the Pope, this website is doing your faith no favors. See this link to another page on that website.
http://www.truecatholic.org/v2ecclesio.htm#ecumenism