How to customize Silverstripe 3.0 ModelAdmin - php

Question

I'd like to do a number of small customizations on the ModelAdmin.
I'd like to change the text on the 'Add' button to one that is different from the original DataModel.
I have a has_many relationship. I'd like to hide the ability to 'link to existing' so that one cannot search for other 'skills' as per below.
I have the following in the Model:
public function getCMSFields() {
...
$characterSkillsField = new GridField(
'CharacterSkills',
'Character Skills',
$this->CharacterSkills(),
GridFieldConfig_RelationEditor::create()
);
$fields->addFieldToTab('Root.CharacterSkills', $characterSkillsField);
...
}
ANSWER to #2:
// Add the relation editor.
$config = GridFieldConfig_RelationEditor::create();
// Remove the ability to search and link to other skills.
$config->removeComponentsByType('GridFieldAddExistingAutocompleter');
$characterSkillsField = new GridField(
'CharacterSkills',
'Character Skills',
$this->CharacterSkills(),
$config
);

Answer 1

regarding #1:
add the following to the model class that's managed by the GridField (e.g. 'CharacterSkill') :
private static $singular_name = 'foo';
private static $plural_name = 'bar';
don't forget flushing the cache afterwards (add '?flush=All' to the url).
the preceding will set the button name to 'Add foo', but it's also possible to set your very own button title, using the following:
$config = GridFieldConfig_RelationEditor::create();
$addButton = $config->getComponentByType('GridFieldAddNewButton');
$addButton->setButtonName('my button name');