when I worked on an FAQ page project I found out that most of our users land on that page:
- only when they have a problem by clicking the FAQ link on the home page (we renamed it SUPPORT and FAQ was a sub-category)
- only by searching something using the global search and in case of zero results by clicking the link “go to the SUPPORT”
having this in mind we tried, as much as possible to redirect users to a specific point of the FAQ page with the related accordion open by default.
We noticed that, in most of the case, the users were leaving the FAQ page very soon because the information was fitting (or partially) their needs.
To answer your question:
- according to my experience the accordion panels are a good UI pattern for the FAQ page
- users are not willing to read the FAQ pages (indeed is a boring task)
- if they’re redirected to a specific section (or accordion) they will grab the info and then leave the page
- the expand all could be a secondary action, even if in my opinion is not adding value to the UX of the page/section. If in terms of development is cheap, you could provide this feature. If it is a KPI for u, then you could track the click-through rate
I hope it helps