>>24971198100% the biggest sin of DP are the inaccessibility of the new evolutions, which is directly related to the poor pokemon availability and distribution.
Platinum does a very good job of fixing this; Platinum also mostly fixes the E4 and Champion teams, which had previously ranged from horrendous to decent. Won't say Platinum is a perfect game but it's highly highly superior to DP.
I think the big issue with translating RSE into ORAS was that Emerald had Wallace as Champion instead of Steven and GF clearly wanted Steven as Champion, since he's the more popular character. They decided to remake RS for the main story and then try and make up for Emerald with the Delta Episode. Obviously it did not pan out well and fans were disappointed. However with DPP, the only significant story changes are switching to Giratina with the main story and having a Heatran post-game story. Expect the DPP remakes to feature a Dialga + Palkia main story, with the initial exploration post game being the Heatran story and then they'll do a Giratina-episode as the epilogue, Cyrus will probably get killed or left in the Distortion World to finish the story.
