1. "The health is too low" - Health in core has always been 100, in every CoD, that hasn't changed, so stop with that. What is a little different compared to BO2 is that in Ghosts, even the fast firing weapons kill in 3 shots up close, whereas in BO2 they would kill in 4 (think of the Type 25 and most of the SMGs). Those guns kill in 3 shots here, so its like they have Stopping Power built in. MW3 was the same way with several weapons.
2. "I die in one bullet but everyone else takes 3-4" - You're dying in the same number of bullets as everybody else, its just that from your perspective, all of the bullets are hitting you at once as opposed to one at a time. This is no different than other IW CoDs where bullet damage is historically higher. Also, killcams are also NOT ACCURATE. They never have been. For more on how CoD online works, read this forum post by someone more knowledgeable on the subject than pretty much all of us: