replacing wp-config… a safe time saver?

1) To save time I installed WP using Fantastico. I created a few test pages etc.
2) I wanted to change my database name and database password etc, so I set up a new database and user in cpanel.
3) I created a new wp-config file with the corresponding new database name etc
4) I replaced the old wp-config file with the new one via ftp
5) I then went to my site and as expected came to the install page – it was as though I had just completed a fresh install of WP. All the old “test” pages where not there- (which was fine).
6) I did the usual- completed the form, user name, password etc…
7) And everything worked fine. Great? Or was this a bad idea?

This seemed fine. It saved me having to upload the core files etc which is an issue for me as my internet connection is slow where I am, so fantastico seemed like a good option, to kick start my install…

Can some one tell me if this was a bad idea?
Could I “break” something using the above method?
At the moment everything seems fine- I’ve had a good check, but I’m just wondering if this method has any draw backs or risks that aren’t immediately apparent?
Thanks loads in advance!
Carro