Form with a lot of input fields, should i use all $this->input->post( or

[eluser]123wesweat[/eluser]
1/ is there a quicker way???

Code:

$data = array('user' => $this->input->post('user'),
etc.
)

2/ another question about set_value. I notice only input fields with rules have their value set other fields are empty when a form doesn't pass form_validation->run()

3/is one controller to display a form and validation a form good pratice??

4/should i always use trim|....|xss_clean for all input fields storing in a DB??