Preaching is different than the issue of the text of the Bible. The NIV IS different.
I did not find any difference in the meaning of the example you gave.
I used to get hung up on all the different translations, and why there were so many. Translating from another language, and another time is difficult at best. Some Greek words have five English meanins.
There is also 6 billion people in the world, and just maybe we need all these different translations. 2 people could read the same sentence and interpret it differently. So you should just pick the translation that you feel most comfortable with, and start from there.
It's what's in your heart, and your desire to seek God that will get you the true word of God. God places a desire for us to know Him. It's just up to you to accept it or not. I think any bible is a good enough plce to start looking for Him. I feel I understand the bible so much more now, with the help of the Holy Spirit.
As far as the new teachings of Jesus, I don't even see the need to add something to the bible. There are plenty of books out there, where people relate the word of God to today. Take a look at the Purpose Driven Life, a huge best seller. I think that book is great.