I am having 3 weird issues that just started happening

1st issue:

I am playing and when i use the Missile Launcher , the gun itself disappears sometimes , but all other weapons look fine

2nd issue:
Sometimes the entire screen goes BLUE for a few seconds when i am inside a structure where its dark (the Train Depot for example) usually right after the night vision shuts off

3rd issue:

I get to the part where i am at the Airfield , i get to the tower and go to the top and get on the radio , after that , if i die , i fall thru the building like its not there , each time i respawn (from the Auto Save Point) i