I hope he's not listening to this right now or the gift wouldn't/won't be a surprise anymore.It's Supposed To Be Hard! Otherwise, Everyone Would Do It!
Arrgghh!!! These would problems! 
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You may be right that hope has an influence here, but let me explain these in a different way.
1. I hope he's not listening to this right now, or the gift won't be a surprise anymore. = I hope he's not listening to this right now, because [if he is (listening)], the gift won't be a surprise anymore.
Here we have a so-called "real condition". The situation itself is such that he may certainly be listening as the statement is uttered. Events are unfolding in real time. The fact of his listening is a distinct possibility in the real world. "What could be in this world" is that he is listening. And "what could be in this world" is that he is not listening.
2. It's supposed to be hard! Otherwise, everyone would do it! = (It is hard!) It's supposed to be hard! (because) If were not hard, everyone would do it!
This is more like an opinion than the example above. In any case, we know that in this world, it is hard. Don't let the semi-modal supposed to fool you. It implies that "it is hard". The otherwise represents the hypothetical idea that it is not hard. So this negative idea is in the world of "what could be if things were different."
But note also:
3. It's a good thing he's not listening to this right now. Otherwise, the gift wouldn't be a surprise anymore. = It's a good thing he's not listening to this right now. (because) If he were listening to this right now, the gift wouldn't be a surprise anymore.
Note the difference between 1. and 3. Here we know that he is not listening, so the word otherwise opens up a situation in the world of "what could be if things were different".
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To summarize: Example 1 introduces a real possibility. In the real world he may really be listening. We don't enter into the world of "what could be if things were different". Examples 2 and 3 introduce only hypothetical possibilities. In 2."what is" is that it is hard. "What could be" is that it is not hard -- which we know is not so in the situation presented. In 3. "what is" is that he is not listening. "What could be" is that he is listening -- which we know is not so in the situation presented.
CJ