I ran through the same issue when I refitted my "new to me" boat. I did a lot of the same worrying over the name change.
Luck is what you make of it. If you believe in the "bad" luck of changing the name then do what I did and do some good luck things to off set it. Remove everything with the old name on it, Christen the boat with your bubbly of choice, and finally - Go sailing.
For mine, she sunk under the name "Emma Rose" and that can't have been a very lucky name so I've convinced myself that it's luckier to change the name.
here's my website:
www.sailkismet.com
Ryan