You're right about spoilers
Thats fair
About voices - no, only subs. About backgrounds for the texts - I didnt find the way to do it
About hotspots - i didnt get it. Hotspots are active areas, right? The text of the hotspot appears on the top of the screen. There are hotspots there
and what you're talking about is pixel hunting. And i think there should be pixel hunting in such type of games