Give RDM a new tier of Dual Wield with 0 Delay reduction. Then add a spell that lowers delay while Dual Wielding. Think of it like Temper, in how Temper gives RDM Double Attack, without it actually being the trait, then with more skill you get more DA. Well this spell would just basically give you an enhancement on your Dual Wielding. So say at the start its 0% reduction from the trait, then with the spell you get -5%, and then have it progress as Temper does, ending at -20%. This would put RDM at a level of delay right between DW 2 and 3. This would give RDM access to Dual Wield as it has long been asked for, but keeping it unique like Temper was.

Obviously like this post if you, ya know, like the idea and all that.