Lets get started.
First and foremost:
-Window mode is busted, you need to play in fullscreen or else it doesn't update the graphic frames correctly with the packets sent and recieved (evidence obtained using wireshark and filter expressions), causing you to send and recieve the same packets over and over, thus you see the resulting issues with frame delay, crashes, lag, stutter, disconnects, and overall annoying online gameplay(evidence obtained through multiple computers on different networks, being tested with similar results, all with different hardware).