For the Royal Robes, I think there is enough there to build with. The Gauntlet/Bracer question is a difficult one, but might be solved with it being listed as an optional item for the costume in the CRL, as the majority of the time his arms are not visible anyway. This would then go into the role playing of this character and body language of not having your arms visible in every picture taken of you. The LMOs would be the best persons to ask, as this would be a new costume to the TFE and 501st, and it falls under their scrutiny.
For the IK variation, this would also be a completely new costume to the TFE and the 501st, so again it would best be answered by the LMOs. I think that last pic you posted was just an error in coloring that they made the extra items red and not gold. I think there is enough to build this costume as well, with and IK being the base with the added Gold trimmed items making it unique. This costume would also be given its own CRL.
I have linked this post to two of our LMOs, so it gets their attention, and then they can give you their opinions on the matter.