The NIV like everything else that is not KLV is taken from corrupted texts. I trust none of them except the King James Version.You're wrong. There's also the Geneva Bible, which was translated before the KJV, and there are a few modern translations based on the Textus Receptus. But the KJV is certainly the most common translation from the TR.
I aggree in general to what you are saying. The KJV is the first complete version taken from the proper texts. There were others that were taken from the correct texts before the KJV.