Among us 2 sounds great. I wonder how its gonna look like, but let me share my toughts:
1. I think we can all agree that security system is a great part of the game, so if you going to make 15 player games with bigger maps there could be 3 security system. Cameras, Admin and unique one (like doorlog or vitals). One more thing to security system: Make admin as strong as cams. In among us 1 players who want to find sus activities always just siting on cams. Making admin better would give an extra chance to crewmates to make big plays. The admin buff could be that you can see players color or you can see players not just in rooms. All of that gonna make communication sabotage more powerfull.
2. Sabotages has an important role in among us. You just cant make a sequel without new sabotages. My idea is a sabotage what affects artificial gravity. When an impostor use this its reduce all players movement speed. They dont start floating just cant run as fast as they can normally. Another idea is a sabotage which close all doors for a few seconds. I know that door closing is already a thing but it isnt too usefull most of the time.