The issue with the sparks should be fixed. Also if you die while flying you will lose your weapons. This provides a little balance to the weapon menu as it is not as though you can not get the shit free from there. The inconvenience also reinforces players not wanting to die while in flight.

As for the issue with the knife there is nothing that removed the knife from the player so it sound like something client side, unless another player can recreate it.

Please test and confirm everything is working correctly now.