This is where I see a problem.

Can somebody suppress my rights (to share, to sing, etc.), in the form of terms? Is a right is something that I can trade?

I don't understand these issues much, just doubts :-(

You're making some fundamental logical errors here.

Your first premise is that you have these rights. But where's your rationale for that?

The simple truth is that you only have these rights if the objects under consideration are yours. But you have no right to share my books. You have no right to share my house. You have no right to share my property. And you have no right to sing my song.

Unless I give you my permission to do so, of course.

So, your first premise is wrong.

Your second premise is that it's suppression if you were not given all possible permissions. But you agreed to the terms with a free will. No one forced you to do that. No one pointed a gun to your head telling you what to do. In fact, you are free to do the same work I have done to author the work, in the first place.

So, your second premise is also wrong.

I don't know what your conclusion is but it's probably wrong, too, because your premises are.

I was asking whether you can set terms that limit my rights? You are not government, right?

I don't think you understood my 2nd question at all.

No, as i said, I was not concluding anything.

There are basically two contexts the word "right" is used: an moral and a legal context.

If the right you're talking about is an moral one, you surely can trade it. This happens all the time since people differ in moral judgements. For example, some may say you have a right to health. Assuming the premise is true, you can still "trade" it for the (subjective) benefit of smoking.

If the right you are talking about is a legal one, it depends on the law. I don't think, for example, that you could sell your right to vote. However, there are other rights you can sell. For example, copyright gives you certain rights that you may sell or trade.

If the movie theater also restricted your right to write a negative review afterwards, say, it would be a bit dicey.

Some contracts that suppress rights might be defensible BUT the point is that such contract are not apriori valid.

Indeed, your the military example shows the need for limits; there's a reason that only the state can operate with the contract you describe. If a private organization could do such a thing, there would serious trouble on many fronts (private armies = bad things).

False. You do NOT have the right to restrict what I do with "your" ideas, once you've shared them with me - be it software, sonnet, or poem. The government may limit my fundamental freedom by enforcing a limited-time monopoly, but only in order to encourage you to work on your ideas.

It is NOT your fundamental right to have such monopoly indefinitely.

Nobody is restricting you from creating a similar food or software (unless there is a patent, which is an entirely different issue). You have the right to create your version, and I have my right to sell only the product, not the process that made it.

I often wonder what RMS would do if he had the power to enact a law mandating that all software be free software - as a form of "positive liberty". Judging by his writings, I get the feeling he'd do it.

My copyright of a work doesn't restrict your ability to copy the idea. In fact, this is what many Open Source projects do: they copy the idea or a proprietary software, but not the software (ie. the work) itself.