This can be done in the same way as mentioned here

Assuming you can export a list of IDs from MS Customer Insights, then you will be able to ingest that data using option ii) or iii) that I listed above. 

Questions:Yes, you need to pass user.categoryId as an mbox parameter, same process that you would use for any other mbox parameter. Same answer as aboveYou need to use "token replacement" when you create the offer, as explained here. So for example, the content in the first row of your table would r...

In the title you mention "more orders than visitors" but in the description you mention "more visitors than orders", could you clarify which it is?

Yes, if you implement Category Affinity then you can create your Experience in Target where the top item in the table is a dynamic reference to "favourite category", the second item references "second category" etc etc 

There are various Custom Events you can listen to, so you could listen to the "Content Rendering Failed" event and then track that the failure happened in your analytics tool. You could also send that info back into Target e.g. you might want to exclude that visitor from being entered into the activ...

You should use triggerView(), as that's specifically designed for SPA implementations where at.js 2.x is being used

Not aware of a way to control/restrict at individual content level. However, you could manage XFs via folders and then use permissions/user profiles at folder-level to control what can be done with them.

Could you provide a URL where you see the error happening? You can also send it via a private message if you prefer

As discussed via messages, the problem is caused by how the web server is handling certain query string params generated as part of re-direct activities, which can be solved by allowlisting those params