More permissions?

I realize that the permissions system was just overhauled -- which is great and much appreciated -- but I'd like to make some suggestions for additional permissions:

1. can set priority
2. can set assignment (if they can't set the assignment, it's always assigned to self.)
3. can set dates
4. can set priority

I added the following code in hook_form_later to achieve this the first two above. Note that it's a role named 'youth' with a key of 4 that I want to remove those fields for. You will also see that if a 'builder' is also a 'youth', we don't want this code executed.

case 'to_do_node_form':
	
	global $user;
	$role_ids = array_keys($user->roles);
	
	// User is 'youth' and not 'builder'
	if (in_array(4, $role_ids) && !in_array(3, $role_ids)) {
		dsm('user is a youth');

		if (isset($form['assignment']['new_user0']['#type'])) {
			$form['assignment']['new_user0']['#type'] = 'hidden';
		}
		if (isset($form['assignment']['new_user1']['#type'])) {
			$form['assignment']['new_user1']['#type'] = 'hidden';
		}
		if (isset($form['assignment']['new_user2']['#type'])) {
			$form['assignment']['new_user2']['#type'] = 'hidden';
		}
		if (isset($form['assignment']['mark_permissions']['#type'])) {
			$form['assignment']['mark_permissions']['#type'] = 'hidden';
		}

		if (isset($form['assignment']['self']['#default_value'])) {
			$form['assignment']['self']['#default_value'] = '1';
			$form['assignment']['self']['#type'] = 'hidden';
		}
		
		if (isset($form['assignment']['#type'])) {
			$form['assignment']['#type'] = 'hidden';
		}
	}
	
	break;