I have been in a debate with people about rdm as a front line job (DD) for a while, I know for a fact rdm can DD, I have done it. I have kept up with AG mythic sam, aeonic blu, empy drk, mythic thf, aeonic thf, the list goes on.
Rdm is seriously on the verge of being way over powered, the dmg really isn't that bad and SE has to be extra careful on the gear they give rdm or it will become bandwagon on dps.
The only things rdm really needed was m.acc bonus which was addressed with the Feb update, outside that they need to increase the potency of dia/bio, poison, para, slow and make mythic worthwhile. As it stands there is literally zero reason for rdm mythic outside convert and we get convert bonus in gifts, only 1 self cure away from being topped off.