How can I correct a wrong 'Personal Profile' address when enrolling in Apple Developer Program?
I fixed it. Don't know why, but I know how.

During the enrollment process, I had logged into My Apple ID to fix my address (only to find out that it was already correct there). Then, I opened up iTunes then went to the menu item Store > View Account. Once again, my address was correct there too, so I exited out of there.

From there, I decided to cancel the Developer Program enrollment, to which the Apple site replied that it had saved my enrollment-in-progress. I started the enrollment over again (though it had much of my previous information retained).

At that point, it had corrected the address by itself.

In short: log in to My Apple ID, then View Account on iTunes, cancel enrollment then restart enrollment. Fixed (for me, at least).