> 1) Are there any option to move the cursor to the start of the candidate
> after the search? I see that there is an isearch-other-end. But it is
> not a custom but an internal variable. Now I am using a hook but it
> seems a bit hacky.

I agree that isearch-mode-end-hook should be customizable.
Then initially we could provide at least one choice -
a hook to move to isearch-other-end on exit: