I posted the question with the motivation that it could indeed bring value.
Then @tocho posted a comment that - depending on the point of view - had a valid argument and while I don't think it's a "shopping list" question, I somewhat can see that the question may well attract spammers and co., which might degrade the value of the question in general.
Therefore, I flagged my own question for moderator attention with a deletion request, just to discover that (seconds later) a new and positive comment pointed here, stating that the question might have some merit. Looking around, I tend to agree and I am not sure if it wasn't a mistake to flag my own question for deletion. Why? Because my question isn't the only one of it's kind here. It should therefore be on-topic.
Alike questions do exist…
Personally, I'm not sure where to take it. I mean, it should be noted that there are alike "list" questions which seem to be regarded on-topic. A random example of such a question is “Is there online eBook authoring tool which can produce ePub and PDF formats?”. To me, this is as much a "shopping list" question as my question is, resulting in similar link recommendation replies as my question does. In fact, the example question even goes beyond that, as it asks for "product recommendations", which is more "shopping-list" than my question. At least from my point of view. And to be sure no one thinks my example wasn't random enough, let me point to another random example which results in similar "product recommendation" answers: “Clean up converted ebook”.
Letting the eBook community decide…
Oh well, may the moderators and the community decide what to do with my question. Personally, I won't be angry if it stays live (I mean, there was a reason for me to post it in the first place). But the world won't fall apart for me if the community decides it is best to delete my question.
See, in cases like these, I tend to go with the flow and comply with the general consensus for the benefit of the community. If you think it should stay, feel free to ignore my deletion-request flag. And if you think it should be killed, be my guest. It's up to you, dear ebook community. Whatever you decide, you got my humble “OK” on it.
The need to draw lines…
Generally, I would like to advise that we — as a community — make sure we don't flag questions before having set up exact parameters of what is allowed and what not. Anything else would be wrong, because it would be non-constructive for both Ebooks.SE as well as it's current and future members.
I have edited my question in the hope it now is more well defined and more specific/detailed. Though, I could not modify it in a way that it would not attract references and links. On the other hand, I added an example link which should make clear what the question is asking for… alike quality references.