Here is one suggestion for explicit data types. I have been working for some time with Access Basic and they have a declaration
which you can place in the top of your file, and you then have to declare variables with type and get error messages when you access an undeclared variable or assign a wrong value to it or use it in a wrong context.
For mission critical applications this can be real important.
And it still allows to run old code which does not use explicit variable declaration.