I have a client with an entityform with over 100 fields (trust me, I begged with them to lessen it). I need to send an email using rules with all of the fields exactly as they appear on the form. I don't want to have to manually add all of these tokens to the email and I also don't want to have to manually update the email with new and/or removed fields every time they change the form. Is there any way of using a token that calls all of the fields on the form and maybe even uses the view mode?
This is already handled in the Entityforms Notifications sub-module the way you are describing.
There is a view mode called "Email". That view mode controls which fields show up in the email. This is done via a token in Rules.
In Entityform 1.x this token is controlled via the Entityform module itself. In Entityform 2.x this is controlled via the Entity to Text Module.
I think there is some problem in Entityform 1.x with showing fields with multiple values. But this should work in Entity To Text. You could also just use Entity To Text with Entityform 1.x. Just replace Entityform 1.x token with the Entity To Text token in the Rule.
If you are interested this handbook page should probably updated with this information: https://drupal.org/node/1679794
I guess you have an Email Template with all your fields/tokens, so that you can call that template in Rules module Rules.
Refer Previewable email templates. With the help of this module, you can create a template with N number of fields/tokens.
This module has integration with Rules, you can trigger any action, whenever you wish to any event to occur.
It's very handy.