It's later than I hoped, but I've finally got the time to write up the DBF guides for NBA Live 2003 as I did for NBA Live 99-2001. I've finished the players.dbf guide except for some specific accessory values, which I will research over the next couple of days.
I don't know if I'll research the Scouting Report values, but if anyone wants to submit that information, I'll gladly give you credit for it. I believe they are similar to previous versions (ie. same values relate to same kinds of strengths and weaknesses) but NBA Live 2003 just uses different sentences in the Report.
I'll hopefully get through the other DBF guides this week as well, and hopefully add some more specific editing guides such as adding a custom team, adding/deleting All-Stars etc for convenient reference.
My apologies for being a bit late with this, hopefully it will still be useful.