To start off, we have made some edits to your question as some parts seemed unclear. Also, yes, the COVID-19 crisis has impacted how we live and work in the near future, if not the long term. Many schools, colleges, and universities are slowly moving online, while some are in the process of doing so, depending on when their academic year begins.Anyway, coming to your question, there are actually two queries, one about making PPT presentations and the other about coming up with guidelines for writing recommendations in research. Let’s take the second one first as that comes before developing the presentation.Recommendations usually come toward the end of a research paper, in the Discussion section. They are an outcome of the findings of your study and are meant to provide solutions for the problem you are studying. So, in your case, you would need to first conduct the study, and then, based on the findings, write the recommendations. However, if you only need to talk abou how recommendations in a study are written, for that, you can conduct a literature search. Reading up on relevant documents will help you come up with guidelines for writing recommendations. Here are some articles...

Firstly, the topic title isn’t entirely clear. Perhaps the second ‘choice’ is not needed, and you simply mean ‘The choice of academic sources.’ By this, you perhaps mean how to choose the relevant literature in a literature search. If so, here are some relevant resources:Tips for effective literature searching and keeping up with new publicationsHow to make Web searches more preciseTips to identify whether a source is scholarly and reliableComing to the presentation part, there are actually multiple activities involved. First, you need to get your content in place (which will come from the literature search mentioned above). Then, you will need to plan and prepare the slide deck. Finally, you will need to practice your presentation – in order to deliver it efficiently to your audience. For these various activities, you may find the following resources helpful:How to use visual aids to make your oral presentations better [Course]8 Tips for presenting a paper at an academic conference9 Tips for presenting at an academic conference [This is a slide-deck version of the previous resource, as you specifically asked about a PPT presentation.]All the best for your presentation!

Re: need to address all sub-topics/ sub-themes I suggest to ask the conference organisers who invited you to speak whether or not they would like you to address all the sub-topics. If they have no preference then speak on the sub-themes that are of greatest importance and interest to you, as this expertise is why you were invited. Re: references in keynote address Regarding references, these can be boring and unhelpful in an address, so I would leave them out. However you need to ensure that you maintain academic integrity, so if you use another researcher's ideas or data then you must give them credit. I look forward to others' responses.

Your question was not quite clear. I have edited the question title assuming that you want to know about presenting a research paper at an academic conference. Presenting at an academic conference is an exciting opportunity. There are quite a few things that you need to keep in mind before making a presentation:First of all, prepare an abstract of your paper such that it points out why your paper would be interesting to the readers and why it should be selected for the conference. Once your abstract is accepted, you can begin working on your presentation. Make sure your presentation slides contain more pictures and other visual elements and less text.While preparing your notes for the presentation, keep in mind the time limit allotted. Practice your presentation before a friend or a mirror. Also, it’s a good idea to familiarize yourself with the conference room and test out the technology you wish to use before the actual presentation. While presenting, bring out the key points of your presentation, but make sure you adhere to the allotted time limit. At the end of your presentation, you must allow some time to answer questions that the audience may have. It’s a good practice to hand out...