Regarding TSCO:
It sounds like Jordan changed the key around a little. I'm not sure.
Everything sounds the same chord-wise/musically (besides the obvious extra notes which I love). Then again, I have some relative pitch, but I don't hear anything out of place from the studio version.
As for his melody choice on the last verse, I can say that he was probably just trying something different. Same key, but higher notes, and different intervals between the notes, and it did sound a little bluesy (though not much). I do this sometimes when I am playing songs on my acoustic, and I know I can reach those notes singing, and I starting a new melody line on a different note...if you feel it out starting on that note and can stay in key, your melody line will change and sound different, but still in tune with the key of the song. I personally though JLB did a fantastic switch there.