First off:

copyright != license

They are two separate concepts, and each affect creations in separate ways.
_{I used the site tags so you can click-through for additional research.}

Some definitions:

Copyright

Copyright is a legal concept, … that grants the creator of an original work exclusive rights to its use and distribution

Licensing

an authorization (by the licensor) to use the licensed material (by the licensee).

And the phrase “All rights reserved, …” is an assertion of copyright over a particular creation. In other words, when you place the term “All rights reserved, 2014 Kernonnes” then you are stating that a) you created the work, b) you are claiming your full rights under copyright law (generally the Berne convention applies), and c) you are not releasing your rights to the creation.

Your question:

So to sum it up I want to use a license to stop others from selling and distributing my themes, while at the same time letting others use the code if they want to.

You’re not clear in how you intend to allow others to access your code so I’ll cover a range of options.

You are correct in that you need some sort of license to permit some amount of distributing and using your code.

Here are some options:

• You want to give away your code, and you don’t care what others do with it.

You can pick from a wide range of free, open-source software licenses. But I’ll skip over the rest of this area since you specifically said you don’t want end users doing some things with your code.

• You want to give away your code, but you don’t want others to give it away

You’re going to need a more specific open-source license than the more popular OSS licenses. OSI (linked above) provides a good overview of the various licenses that are available.

You do not want to write your own license. Don’t even bother considering it – it’s a rabbit hole that will lead you to much frustration and a likely unenforceable license.

• You want to give away your code, and you want to sell your code, and you don’t want others giving it away.

In this case, you need to consider dual licensing. It’s possible one of the open-source licenses will assist you in this effort, but they may not. You’ll need to do a lot more research before you head down this route.

“All rights reserved” will not have the desired effect. Without specifying a license this will imply general copyright, which won’t let viewers of the code copy it in any way: no reselling, but also no noncommercial reuse. Dual licensing also would not be suitable. In the event software is available under two different licenses the licensee can pick which terms they prefer to abide by.

Researching the answer to this question lead me to a brief but comprehensive thread on this topic at Stack Overflow. In the name of semantic content, a TL,DR:

None of the popular free software licenses prohibit commercial sale of freely obtained source code (although in practice the GPL discourages it). This is a philosophical thing; cf. linked SO article. The closest license to what you’re asking for is the Noncommercial version of the Creative Commons license.

Creative Commons discourage the use of the CC license for software, but I would say this is a corner case. A WP theme is a creative work which happens to contain code.