Have you looked at the Swift error model? I really like their design. They use a dedicated try statement to mark call sites that can fail — note that try is not the same as try...catch — Swift has an additional block construct for catching errors. This design makes sure that you always know where errors can occur when reading the program code, but avoids all the ergonomy issues you mention.
Your model sems to be every similar to the traditional implicit model used by languages such as C++, only that you allow switchign between the implicit and explicit error propagation. I am not sure how much this is useful in practice, as it creates inconsistency.
Your model sems to be every similar to the traditional implicit model used by languages such as C++, only that you allow switchign between the implicit and explicit error propagation. I am not sure how much this is useful in practice, as it creates inconsistency.