I want to write a book about an idea/story I've had for many years that I find many will truly enjoy when furnished out; however, I don't want this to be "open-source"; I don't want anyone to be able to re-use it as their own and profit like it's their work (as a Creative Commons kind of license).
Is there any way I can "protect" ideas/characters without a copyright? Any simpler, easier, freer way?
Copyright is free. Assuming you're living in a country that's a signatory to the Berne Convention, which you almost certainly are, your work is copyrighted as soon as you record your ideas.
Registering copyright may cost something, depending on where you live, but it's of dubious value, really. In the US, for example, registering copyright allows you to sue for punitive as well as compensatory damages, but it's really pretty rare for a copyright case to go that far anyway.
Once you write something, you officially own the copyright to it. That basically means that nobody else can use your story, characters, or setting to create their own story, because it would be considered a derivative work. Basic copyright laws protect the owner from such acts.
To help ensure that other people do not assume that your work is "open source", simply add the following tag: "Copyright 2015 by Author Name". By doing this, you make a public declaration that your work is under copyright protection and warns others that they cannot freely reuse your content.
Part of your question also mentions the word "ideas". You should be aware that ideas themselves cannot be protected under copyright. If you come up with an idea to write a story about a wife shooting her cheating husband, there is nothing that will prevent somebody else using that idea to write a story about different people in a different setting.
The best way to prevent anyone from stealing your idea, is to have a rubbish idea, and write it badly.
Anything more than that and what you write will become part of the canon and people will build from it.
You're protected from someone stealing the details of your story, but that isn't generally how work is copied.
I remember when I first saw Iron man, thinking that I'd really like to see a story that was based on Pepper Potts. with all of the other mayhem going on in the background.
In that context I may have an issue calling her Pepper Potts, and the superhero couldn't be Iron man, but I could write something that built on that story by changing the names to protect the guilty (i.e. me)
Romeo and Juliet, is probably one of the most known stories in the world, it has been copied, rehashed, built on, stolen from. Imagine what we would have lost from the world if Shakespeare had been worried about someone stealing his ideas.
Stop worrying, get writing. If its good, people will steal ideas from it, take it as a compliment, and move on to the next thing they can steal.
We're here to be creative, we take ideas from the canon, build on them, and give something new back for others to build from. If you don't like that thought, go be a bricklayer.
