no, those are absolutely not fixes: you have to remember to use "using", "with", etc. whereas you have to go out of your way to circumvent RAII

Non-issue. You can use fopen in C++ and remember to fclose, too.

No, every time you have something that sound like "you just have to [...]" it means future bugs that were entirely preventable. The only correct way in c++ is to wrap it in a unique_ptr or handle type so that fclose gets called automatically when you are done with the resource

Use static analysers, just like you have to do on C and C++ to handle many of their flaws.