In the quest guide, It's written "Yellow Piece acquired in Blackview City. You will need both a Dull and Shiny key, which are found just below the Silver Rise Peak, and Silver Rise Forest"; Where in blackview city do I go to get it?
The Infiltration battle event is repeated if the healing station in the Fox hideout was the last used healing spot before blacking out (After completing the event)
I think it's a bug. Try deleting the game and then downloading it again, if that doesn't work, I'd suggest reporting this in the Troubleshooting section
I'm pretty sure you're not supposed to visit Jenny. Go to the underground city and talk to the dude (i'm sorry its been a while since i last played, i forgot a lot of the names)
Yeah, in the conversation between Melia and the professor, Melia asks where he kept her audition tapes and he replies with "in the wardrobe", and if we interact with the wardrobe after this, we get the CD which we can view by interacting with the PC
Reset? You aren't that far into the game, so you can skip all the dialouge by holding the "X" key. Probs will take you like 10 minutes to get back to where you are.