I know more feats are probably on the way, but I'd personally really like Duel Wielder to be a priority. It's already a tough sell for a rogue to be in melee, harder when you can't even set up to have them use two Rapiers. And while I understand if this can't be a priority, but if more subclasses are added, I'd love to see the Rogue get the Swashbuckler class. They really make for fun melee rogues.
Also, I think the rules for hiding need to be more clear. I've had my characters hiding behind full cover, and still not have line of sight broken. I'd assume that when the hide button is highlighted, any red square would be in an enemies line of sight, but that doesn't seem to be the case. It would be nice if this is made more clear, so the player doesn't waste movement trying to find a good hiding place. And since hiding is now possible in combat, it would be great if Island Halflings could hide behind allies. I'd actually prefer that over the Rope Dancing thing they get instead.
Finally, Lowlife Background, and the Rogue class both provide thieves tool proficiency. Now if I were to make a Urchin Rogue on DnDBeyond, it would allow me to swap out the Thieves tool proficiency from Urchin with something else. Should be the same here, probably for any instance of Background tool proficiency overlapping with class, though Rogue and Lowlife are the only ones I know off the top of my head. I actually made a Rogue with a spy background, because the Lowlife option gave so little in comparison.