One other thing that has me tending away from the Maul’s saber idea (and not to criticise the idea or your work, PeterPan), is that there’s a risk that we take away from the power of a couple of other ‘good guy uses red saber during an emotional time’ moments. Off the top of my head, we have:

In ROTS, when Anakin wields a blue and red saber to decapitate Dooku, illustrative of him making the transition to the dark.
In Tartakovsky’s 2003 Clone Wars miniseries, when Anakin uses Ventress’ saber in anger against her, in a moment that’s shot a lot like Luke hammering Vader at the end of ROTJ, showing an early tending toward the dark.
In the Clone Wars CG series’ episode Revenge, where Obi-Wan uses Ventress’ saber in anger against a resurrected Maul, in a moment where Maul’s really goading him about the fact he killed his master, illustrative of Obi-Wan really feeling the pain of that loss.

(I compare the last one, about Obi-Wan, to his behaviour in TPM, where really he wins because he’s just had that slow, meditative moment in the pit, rather than acted in anger at the loss of Qui-Gon. In TPM, when he acts, it’s more peaceful and Jedi-like.)