The footstep issue seems to differ from person to person. I was participating in FNB the other day and killed tons of people trying to sneak up on me. They are aware of this issue and it should hopefully be sorted out soon.
Technically you aren't dying instantly, it just appears that way due to the netcode infrastructure. This is the TTD(Time To Die/Death) issue you keep hearing about. I can assure you the devs are working hard to fix this in addition to other TTK (Time To Kill) feedback sent their way.