Tessmar:
When your power went off - your Mac would have legitimately lost the connection to the Time Capsule. If you had a share on Time Capsule open at the time of the power failure - you should have seen at least one popup notification on the MacBook Pro (which would have been running on battery) at the time the power failure occurred - unless you quickly shutdown the Mac before the popup had a chance to occur. Did you actually shut down the Mac - or was the Mac actually sleeping? When I read your initial post - I failed to pay attention to the fact that you had a power failure.
I'm assuming that your Time Capsule and everything else (other than the Mac) went down with the power failure - and that you are seeing repeated popups warning about the disconnect - even after everything has been powered back on normally (as well as the Mac having been restarted?). The repeated popup would be a problem - the initial popup was/would be expected.
I'm also assuming that you are using the Time Capsule as your primary router - as well as using it with Time Machine - to back up your Mac - and that you are storing other (non-backup related) files on the TC drive - which you are backing up once a day (using Carbon Copy Cloner) to your external Seagate firewire drive attached to your Mac? Just checking to make sure that I am clear.
I think you should monitor things for a few days to see if the popup continues - (after you have made sure that everything is freshy rebooted) and also be sure to mount a share on the Time Capsule on the Mac. The popup won't appear unless the Mac thinks there is an active share to the Time Capsule and either falsely or correctly detects the loss of that connection.
I think you should hold off on renaming the Time Capsule - as not to introuduce new variables into troubleshooting the popup.
When you do decide to change your Time Capsule name - you would open Airport Utility 5.6 - select the time capsule - click Manual Setup on the Summary Tab - the first item listed will be Time Capsule Name - you want to be sure that you are chnging the name of the Time Capsule itself - and that you are not changing the Wifi settings and not changing the name of the Data volume on the Time Capsule. To place to change the name is on the second tab which is labled Time Capsule.
Here you can type in a new shorter and more simple name for you Time Capsule. The Time Capsule will reboot after you change its name. Once you have change the Time Capsule Name - you will need to go into Time Machine and reselect your newly reamed time capsule device - as the backup destination.
Here is screen shot - where it says TC01 - that would be where you would type in the new name of your Time Capsule.

It sounds like you were trying to use the guided setup rather than the manual setup - and that is why it was telling you that your Time Capsule is protected by a password. if you are new to the Mac and Time Capsule - you might want to be very careful about making change to the TC setup until you are more familiar with Airport Utility and the Time Capsule.
~Scott