Patt,
So, yes, I'd also like to know if Pages is working (if you've had a chance to try it).
If the partition/volume you were originally using is the the one with the skull and crossbones, then that is not a good thing.
However, if you used CC to copy over your backup to your unused partition and that's the one with the skull and crossbones, then you probably didn't select the right option in CC to copy it over (I don't use CC but there's probably an option to copy over and make a partition bootable and that's the one you'll need).
If you backup is the one with the skull and crossbones, then that's also not good (since it seemed like you were able to boot from this before).
Depending on what programs you use, migrating to El Capitan may be easy or not. For me, going from Mountain Lion to Yosemite took some work and going from Yosemite to El Capitan also took some work as well. But the apps that presented the most problems aren't used by a lot of Apple users. You'd have to let us know what programs you use and then we can let you know how easy/difficult it would be. It looks like iWork '09 does work but we'd have to know the specific version you're using.
So, yes, I'd also like to know if Pages is working (if you've had a chance to try it).
If the partition/volume you were originally using is the the one with the skull and crossbones, then that is not a good thing.
However, if you used CC to copy over your backup to your unused partition and that's the one with the skull and crossbones, then you probably didn't select the right option in CC to copy it over (I don't use CC but there's probably an option to copy over and make a partition bootable and that's the one you'll need).
If you backup is the one with the skull and crossbones, then that's also not good (since it seemed like you were able to boot from this before).
Depending on what programs you use, migrating to El Capitan may be easy or not. For me, going from Mountain Lion to Yosemite took some work and going from Yosemite to El Capitan also took some work as well. But the apps that presented the most problems aren't used by a lot of Apple users. You'd have to let us know what programs you use and then we can let you know how easy/difficult it would be. It looks like iWork '09 does work but we'd have to know the specific version you're using.