I would like to focus on 2 out of the 3 debated questions, as I believe that 2 of them fall into the same category: "Software to live-stream presentations" and "Creating a secure test environment for a programming lab practical". The first, I voted to close as shopping question and the second I voted to leave open.
The guiding principle for me is what would constitute the accepted answer.
I think that the same rationale would also apply for the highest upvoted answer, but first for reasons of brevity and second, because we are talking about the closing of a question, it seems closer related to the OP than the upvotes, I base the following discussion on the accepted answer.
The first question asks for software recommendations for streaming presentations in an academic environment. Framed as such, natural answers would entail what the posters' experiences with such tools were in the past (e.g. Skype, Slack, Teams, ...). Suppose now it attracts three answers, each listing three suggestions with the rationale why the tool did work for the poster (i.e. we are looking at "complete" answers of similar quality). What would the criteria be for OP to accept the answer? What he likes best? What he ends up using? The first answer? In my opinion this ceases to be Q&A and becomes a forum post all inclusive with extensive chat-like commenting. Members of the community will tend to upvote based on their preferences and perhaps even downvote based on their bad experiences with the tools, again, because there is no other inherent quality that might differentiate the answers. Further, what would be the benefit for a prospective reader? Plagued with the same question, happy to have found it already answered, how would he interpret the answers? Simply put, such questions merit a discussion and lists of preferences. I guess that it also could be construed as opinion-based under circumstances, but either way, closing material.
Further, this is the epitome of "boat programming" question. I.e.: "As an academic, what tools should I use for live-stream presentations in order to facilitate lectures, office hours and exams?". The same tools are used in industry, family meetings, online role-playing games, etc. for a reason: the use cases are the same (need to communicate with a group, possibly with video support, share documents, present, etc.). So, the fact that the tool is for academia makes it in no way different or more special.
As for the second question, although it could be seen as a shopping question, there is a another question, more relevant to Academia SE, underneath: how do we secure the integrity of exams that are forced to be conducted remotely. A serious question which warrants serious consideration and quality of answers, which would also be applicable to other readers. This is also a good example, as one can compare the answers in both questions. So, at worst, this question needs some editing for clarification, but I wouldn't consider it a shopping question.