1) No. The loss of life over time is very low due to being based on your max life of 1, as such it can be trivially countered by a small amount of flat life regen
2) You cannot. You can be losing life over time, and this is tracked, but the loss is only applied to your actual life value once it reaches at least 1.
3) Blood Rage deals physical damage, and most CI characters chose to have energy shield because they are cowards. Ususally they recover this shield faster than the damage and thus it never gets applied to life.
In the case of a CI character with no ES, it does kill them in pretty much the same way, but at least this character dies knowing his ancestors are proud of his actions, instead of surviving as some snivelling wretch who needs to hide their life behind some blue mess to feel confidant.
4) As noted above, minimal amounts of life regeneration. If you regenerate at least as much life as you're losing, then you're set.
5) Because you are on full life until the point where the loss accumulates to 1, and this causes that 1 to be subtracted from your actual life. As soon as you actually lose the life, it could be recovered by life on hit, but at this point you are dead.