Can we not use fields and markers in the Subject Line or body Email Reminders?

Juan, all is not lost with this.  You don't have to go back to outlook. There are ways to use notifications to help you achieve this.  Its not the best solution, QB Courier is :), but notifications can help you.

Mark Schnier provided a nice detailed solution to a similar question, check out this community forum thread:

https://quickbase-community.intuit.com/questions/989572-send-custom-emails-to-non-users-no-out-of-the-box-solution-via-notifications-subscriptions-nor-reminders

Keith