Talk about cafeteria Christianity - your citations states specifically that those are the first and greatest commandments and that all others rest on them, BUT not that they are the only ones:
"Do not think that I came to abolish the Law or the Prophets; I did not come to abolish, but to fulfill. For truly I say to you, until heaven and earth pass away, not the smallest letter or stroke shall pass away from the Law, until all is accomplished. Whoever then annuls one of the least of these commandments, and so teaches others, shall be called least in the kingdom of heaven; but whoever keeps and teaches them, he shall be called great in the kingdom of heaven. I say to you, that unless your righteousness surpasses that of the Scribes and Pharisees, you shall not enter the kingdom of heaven."
http://www.biblegateway.com/passage/?search=Matthew%205:17-20&version=NKJV;