I can't duplicate the random screenshots with the Replay Buffer enabled. OBS doesn't have separate directories for videos and screenshots. They're all saved in the Recording Path directory. Try setting the Hotkey Focus Behavior to Disable hotkeys when main window is not in focus. Settings > Advanced > Hotkeys.
You should also do the following:
1. To ensure that OBS Studio has the hardware resources it needs for realtime streaming and recording, we recommend disabling the "Game DVR Background Recording" feature via
these instructions.
2. OBS is not running as Administrator. Because of this, OBS will not be able to Game Capture certain games, and it will not be able to request a higher GPU priority for itself -- which is the likely cause of the
43.4% rendering lag you are currently experiencing. Run OBS as Administrator to help alleviate this problem. To run OBS as Administrator, right click on the OBS shortcut, properties, advanced, check box, ok, apply, ok.
3. Display and Game Capture Sources interfere with each other.
NEVER put them in the same scene.
4. Multiple Game Capture sources are usually not needed, and can sometimes interfere with each other. You can use the same Game Capture for all your games. If you change games often, try out the hotkey mode, which lets you press a key to select your active game. If you play games in fullscreen, use 'Capture any fullscreen application' mode.
5. Your GPU is maxed out and OBS can't render scenes fast enough. Running a game without vertical sync or a frame rate limiter will frequently cause performance issues with OBS because your GPU will be maxed out. OBS requires a little GPU to render your scene.
Enable Vsync or set a reasonable frame rate limit (60) that your GPU can handle without hitting 100% usage.
If that's not enough you may also need to turn down some of the video quality options in the game. If you are experiencing issues in general while using OBS, your GPU may be overloaded for the settings you are trying to use.
Please check our guide for ideas why this may be happening, and steps you can take to correct it:
GPU Overload Issues.
6. The encoder is skipping frames because of CPU overload. Read about
General Performance and Encoding Issues. You should be using the QSV/Quick Sync Video encoder instead of x264.
If still having issues, post new log.