We just returned from a 5 night stay at Pixar Place. I only caught a glimpse of Bing Bong once in the lobby.... it was late afternoon timeframe, and we saw Joe Garden playing once, maybe around 5ish? I never saw any specific times listed, but we also weren't set on trying to see them.
Yes, the games area near the pool is accessible without a room key since you don't need a key to get into the elevators. Just take the elevators to 3rd floor. When you go outside, you can walk through the games area, outdoor seating area, and past Small Bytes all without a key, and then when you want to walk up the half flight of stairs to the pool area, you need to use your key to enter the gate there and they will give you a bracelet showing you're allowed to be in the pool/splash pad area. So based on our experience, we could get to everything without showing our room key until we wanted to enter pool and splash pad.