On these two commandments hang all the law and the prophets.

Doesn't say that the old laws are not to be followed. The most logical interpretation is that all the old laws follow from these two (which is nonsense, but, hey, it's the bible)

So, okay, there may be a few places in the Bible where there are some contradictions. I'm sure they're very minor.

Like the two totally contradictory creation myths in Genesis? Or take a look here: http://contradictionsinthebible.com where there are nearly 400 contradictions (some are quite nit-picky, others substantial)