First to try and answer some of your questions.
There is no way to change the partition set-up without using third party software and then there is always a small risk something will go wrong. Partition Magic is probably the best known partition manager, but not the only one. You really need to know what you're doing before embarking down that road.
Ghost will not dissolve anything on expiry, it will just cease to function.
Now, to address that spare partition.
All the computers I set up now for my family (and clients with their permission) have at least one extra partition - like the one you're talking about.
I reconfigure My Documents on to the secondary partition and recommend that all personal files live there.
Why? Because if you get a problem that is so severe, you need to reinstall the operating system from scratch, providing you don't format that secondary partition, all your personal files should remain safe. I've lost count of the times people have lost photographs and valuable data because they haven't backed them up and this is the next best thing.
Once you get the machine up and running again, you should be able to view that partition and all the files on it.
So in my view, your second partition is not a inconvenience, it's a bonus.