Ghost is a stealth perk, which should be used for flanking and being sneaky. However, A LOT OF PEOPLE use it to camp so they can't get naded or overrun. To keep it fair, Ghost needs to be in the same tier as a perk that helps you win gunfights, such as sleight of hand. So now ghost flankers have to win gunfights by suprising the enemy because they are off the radar. You either suprise the enemy and kill him shooting in the back or side, but if you fail at being a good flanker and meet the enemy head-to-head you have a severe disadvantage.
And for spawn camping, if you get killed 4 times in a row within 7 seconds of spawning you get to choose where you spawn along your team's spawn points.