I can understand that you are not willing to disclose your name or other information, but it is definitely not because 'someone can steal your idea'. Ask any businessman and he will tell you that it's bullshit - ideas are worthless, every single one of them, no one would ever steal it or make some kind of damage to you. It's all in the process and your ability to make that idea come true, not idea itself.
It's true that ideas are worthless, but some ideas are very worthwhile to people. If I had given you an idea of how to build an entire, fully functional, autonomous drop shipping business in a very profitable niche - you'd steal that idea in a heartbeat. Execution is very important but a bad idea will always lead to failure.
That's why ideas can be quite valuable and based on his background - a very strong background in E-commerce - an idea like his may be worth more than you know. Let me give you a real-life example: my friend's professor is an entrepreneur; a serial entrepreneur and a very good one. The only reason why he teaches at a university is that he flies into the vicinity of that area every week to check on his businesses (real estate) and he likes to teach, but he doesn't need the money that comes with it.
Anyways, he was just like OP and was very good at executing businesses. He came up with a new idea for a business that employs psychologists for mentally disabled people. He went to a group of psychologists and proposed the idea to them. He asked if they'd like to come on and invest in his idea. They said his idea "wasn't good" and shooed him off. Later, he found a competitor company that was executing his exact idea. He would've failed except he had more money than they had and knew how to leverage his resources.
At the end, he won but after pouring millions of dollars down the drain to kill the competitor that turned out to be those group of psychologists that claimed his idea was bad and later turned around and tried to run off with the idea. All that extra effort was because he couldn't keep his idea confidential when it needed to be. An online forum isn't the right space where you disclose your ideas - especially not BHW.
Another example is Facebook. Mark Zuckerberg didn't come up with the idea, but a group of other people did and they hired Zuckerberg to work on their idea. Zuckerberg took their idea and executed it very well. Today, we know that stolen idea as Facebook. One of the largest companies in the world that is changing the way we communicate forever because of a stolen idea.
(Ok, maybe it's not that simple but that's the best summary I can come up with for Facebook)
Ideas have value but they are cheap. It doesn't cost
anything to come up with ideas, but sometimes those ideas have such
high potential that letting someone else know may lead to the demise of huge profits for yourself in a viable business. You never know. Keep those ideas safe and worry more about executing them than the "value" of your ideas.
As you said, ideas are worthless at the end of the day; execution is what matters. 
