I created a custom list. Then I created a page (wiki) when I used this list as a web part. I'd like to limit the edit permissions for the list (it should be read-only for most users) - so, should I broke the inheriting of permissions on page level and the list will inherit the rights from the page? Or should I manage the rights on the list level? What would you suggest? what would be the best solution? thx.
Do it on the list level.
As limiting the access to your list seems to be the primary goal, you will want to prevent users from editing the list from elsewhere as well. This means, that if an end-user figures out the list's original source (the .aspx to the list itself), the user would have the non-restricted permission-level still applicable there as permissions wouldn't inherit from a page to a list.
Additionally if you one day want to have some content on the page which the users should be able to interact with (e.g. contribute), the page-level actions for restricting interacting with its elements would cause a headache.