Enabling 'strict_types' globally in PHP 7

This is deliberately not possible, because the implementation adopted after an extremely long discussion of scalar type hints was this one: https://wiki.php.net/rfc/scalar_type_hints_v5

It explicitly gives the choice of how scalar types are checked to the caller of any function, not its author, so that:

• if you write a library with scalar type hints, your functions are guaranteed the parameter types requested, even if called by code not written in strict mode (the types are coerced instead)
• if you write a library and want traditional weak typing, you can still make use of libraries that use type hints (because they don't force you to perform strict type checking)
• contrarily, if you write a library and want strict typing for functions that you call, you don't have to require that users of your library also enable strict typing
• built-in functions work the same way as user-defined ones, and existing code runs the same by default
• if you turn on strict typing, you need to change your code to handle it correctly anyway

It's therefore up to you to tell PHP which files have been written to use strict type mode, and which haven't; and the way to do this is using the declare statement.

PHPStorm has an inspection to help you with this:

Essentially no.

Because if you only require libraries that used strict mode you will cause an unnecessary separation of packages.Also consider the strict/weak types option is just an extra in PHP.