Apple held talks with DuckDuckGo to replace Alphabet's Google as the default search engine for the private mode on Apple's Safari browser, the Bloomberg News reported on Wednesday, citing people familiar with the discussions.
That's a bit more difficult. It doesn't allow you to manually type in the address so you need to keep visiting it until Google recognizes that it's a search engine.
I would imagine you can add your own in as well, the same as Firefox allows.
Yeah, it's easy. I recently changed to Kagi. Just had to do a search using Kagi first, then open settings and it was there.
That's a bit more difficult. It doesn't allow you to manually type in the address so you need to keep visiting it until Google recognizes that it's a search engine.