Decline it? I only know when I brought those heart to richard, I get exp and gold. Reward will increase more after you read his mind. As for keys, you wont need to bother bout them, as long as you had all chests or locked door open. There are certain chests where keys are provided, but you can still open it with lock pick skill. I remember I still got quite some keys remain in my quest tab in the previous play through.
