How can I remove and add fields in Mass Update?

Hi everyone,Thank for reading this conversation
I using Sugar CE 6.5.16 and i have two question:

1) As i know that in Module Builder, we can choose field to add on Mass Update, but i want remove some default field on mass update .  What should i do ? I have been try that code on custom\Extension\modules\SCP_Contract\Ext\Vardefs, but it not work.
$dictionary['SCP_Contract']['fields']['category']['massupdate']=0;  
$dictionary['SCP_Contract']['fields']['sub_category']['massupdate']=0;  
$dictionary['SCP_Contract']['fields']['do_not_call']['massupdate']=0;   
2) I want to add Relationship ( Many to One ) on Mass Update . Is it possible?