You still need to think about error handling, and it's not standardized because everyone else will also have to think about it ad hoc.
You'll also still need to think about when to copy and move ownership, only without a type system to help you tell which is which, and good luck ensuring resources are disposed correctly (and only once) when you can't even represent scoped objects. `goto` is still the best way to deal with destructors, and it still takes a lot of boilerplate.
No, but that tends to gradually happen all by itself from my experience, even in solo projects. Because it feels stupid writing something yourself when you have access to stdlib. Also, I feel rolling your own stuff in C++ is a major pita in comparison to C, too many rules to memorize for me.
You don't have to think about exceptions, overloaded operators, copy constructors, move semantics etc.