We're using EPiFind, does that mean we can turn off EPiServer Search, i.e. ?
Or does the CMS need Search for internal reasons?
When installing Find the default search providers are replaced with the Find ones. So you should be OK to switch it of as long as you are using Find to index everything in your site. You can configure which providers are used in Admin > Config > Search Configuration.
Its an interesting question so let me know how you get on :)!
So right now now, under that setting I have everything ticked:
I'm not sure what the difference between Pages and Find pages is for example, but based on this you think we're OK?
The Find pages use the Find provider and Pages uses the built in provider. I would try unticking the non-Find providers and check that the search areas continue to work.