SE has said "No" to this question. SE has taken the position that "human" error is an integral part of the PvE game experience. Thus, they want to the player to have ability to make the mistake of using the wrong skill and breaking the combo.

As for DRG specific, I use a macro which combines "Fang and Claw" and "Wheeling Thrust" onto one button.

/ac "Fang and Claw"
/ac "Wheeling Thrust"
/micon "Wheeling Thrust"