Bumping. The mission "A Safety Feature" in the Power Relay Vault on Belsavis (Tomb area) has been removed for some time. Is there any reason why or was it a consequence of the streamlining done in 4.0? Can the devs add it back in as an exploration mission?

Have you tried switching to the non-streaming launcher? There's a good guide on how to here: https://answers.ea.com/t5/Troubleshooting-Guides-Info/Guide-How-to-Switch-to-Non-Streaming-Launcher/td-p/4867417

Back near 4.0's release, a ton of the Heroic quests were re-structured so they could be accessed and completed very quickly by getting them from terminals and automatically turning them in when done. I understand this was done to make gearing and endgame easier, but by removing the NPC dialogue a lot of the story elements were removed. Whether or not this was intentional I don't know, but I'd love to see these NPCs put back in the game to get the quest from them as well as see the finishing conversations (not at all possible now). An option could be added to toggle the autocomplete for Heroics on/off for players who just want to finish them, just like there is an option to show/hide exploration missions. I'd also like to see the Flashpoint breadcrumbs as well as some of the bonus missions that were removed in 4.0 added back too. They would be completely optional for everyone but would be available for any players who would want to do them.