The 1st question was reopened quickly while the second is on hold. So Mods took 50% correct decisions today.
The second statement in no way follows from the first. The first question seems to have been re-opened after it was edited. The mod who closed it initially then would seem to have made the correct decision to place the question on hold pending the edit that made that question more appropriate. That suggests that mods made 100% correct decisions in these cases.
(emphasis added below)
A diamond moderator should step in ... but not for harmless questions and answers which can be dealt by the community.
There is no SE or M&TV.SE concept of "harmless" or "harmful" in terms of how content should be treated by mods or by the rest of the community. This is a concept you have invented for this meta question. A better way to propose a distinction here would be to explicitly suggest it, such as a meta question along the lines of "Should off-topic and opinion based questions be treated differently from spam/abusive/vulgar questions?" Then inside that meta question, you could propose to call the former type "harmless" and the latter type "harmful". Short of something like that, there's no reason why I or any other user should consider a spam question any more harmful to the SE model than an opinion based question.
Overall, I think we should all keep in mind the following:
Questions are put On Hold, not "closed" by votes and mods
On hold means, "we are not allowing answers to this question until the question itself has been made better and up to the standards of the site". It does not mean "we are permanently removing this question from consideration".
It is totally understandable to feel that an on hold question has been completely and permanently rejected from the site, but it's just not the case. On hold questions are paused and awaiting edits to address problems. That's exactly what happened with one of your example questions, and it shows the system working exactly as it is intended to work.
Edit based on a comment:
The community could do that on its own. Why don't the mods wait a bit for community to reach to that decision.
This seems to suggest that the mods and the community are two different entities that should have separate roles and duties on the site. The mods are a part of the community, which is why it's called "community moderated". To say mods should do one thing and the community do another thing doesn't make a lot of sense. Remember, if five users with enough rep vote to re-open a question put on hold by a mod, then the question is reopened. So the mods don't have the power to single-handedly shut out the rest of the community, in most cases.