如何通过验证规则中的键过滤请求数据？

I am working on a multi-step registration form. In the first step, I need to collect first_name, last_name, and dob, then create a Customer object with only those three fields:

// RegistrationController.php
public function store_profile(Request $request) {
    $rules = ['first_name' => '...', 'last_name' => '...', 'dob' => '...'];
    $this->validate($request, $rules);

    Customer::create($request);
}

The problem is that other fields, such as address, city, state, etc. are also fillable:

// Customer.php
protected $fillable = ['first_name', 'last_name', 'dob', 'address', 'city', 'state', ...];

I intend to collect them in the second step of the registration (in public function store_address()), yet nothing will prevent the user from POSTing those additional fields to step one:

// RegistrationController.php
public function store_profile(Request $request) {
    $rules = ['first_name' => '...', 'last_name' => '...', 'dob' => '...'];
    $this->validate($request, $rules); // won't validate 'address', 'city', 'state'

    Customer::create($request); // will store everything that's fillable,
                                // no matter if it was validated or not...
}

Hence, my goal is to filter $request->all() fields by the array keys defined in my validation $rules variable. Here's my attempt:

$data = [];
foreach(array_keys($rules) as $key) {
    $val = $request->{$key};
    if (! empty($val))
        $data[$key] = $val;
}
// in the end, $data will only contain the keys from $rules
// i.e. 'first_name', 'last_name', 'dob'

First, is there a more efficient/concise way to do it using array_column or array_intersect_key or other, possibly without manual looping? Second, is there a more Laravel-like approach that I am not aware of?

What about only() (and except())?

Customer::create($request->only(['first_name', 'last_name', 'dob']));

or

Customer::create($request->only(array_keys($rules)));

Edit: In Laravel 5.5, there's another solution:

$rules = ['first_name' => '...', 'last_name' => '...', 'dob' => '...'];
$data = $this->validate($request, $rules);

Customer::create($data); // $data contains only first_name, last_name and dob

I would have done like this if I were you:

public function store_profile(Request $request) {
    $rules = ['first_name' => '...', 'last_name' => '...', 'dob' => '...'];
    $this->validate($request, $rules); // won't validate 'address', 'city', 'state'

    Customer::create([
        'first_name' => $request->input('first_name');
        'last_name'  => $request->input('last_name');
        'dob'        => $request->input('dob');
    ]); 

}

or even simpler:

Customer::create($request->only(['first_name', 'last_name', 'dob']));