Guild Wars 2

Alice has low condition damage.
Bob has high condition damage.

Scenario 1:
Alice applies 3 seconds of burning to an enemy.
Bob applies 2 seconds of burning to the same enemy, roughly at the same time.
The enemy now has 5 seconds of burning. How much damage will it take?
Will it be 3 seconds of low damage, followed by 2 seconds of high damage? Will it be averaged?

Scenario 2:
Alice applies 5 stacks of bleeding to an enemy.
Bob applies 3 stacks of bleeding to the same enemy.
The enemy now has 8 stacks of bleeding.
What will be the bleeding damage?
Will the stacks have different damage, based on who applied them?

Scenario 3:
Alice applies 25 stacks of bleeding to an enemy.
Bob tries to apply 4 stacks of bleeding to this same enemy.
What happens?
Would it be different if Bob was the one that applied 25, and them Alice tried to apply more?

Scenario 4:
Bob, who has no Healing Power, gives 5 seconds of Regeneration to a friend.
Alice, who has high Healing Power, gives 6 seconds of Regeneration to the same friend.
How will the healing amount be? Low for 5 seconds, than high for 6 seconds? Averaged?

Thanks in advance.

Scenario 1:
Yes, 3 seconds of low damage, then 2 seconds of high damage.

Scenario 2:
All 8 stacks will tick for their respective damage every second of their individual durations. So, assuming alice’s bleeds last 5 seconds and Bob’s bleeds last 10 sec, and all 8 stacks were applied at the same time, the enemy would experience 5 ticks of low damage and 3 ticks of high damage every second for 5 seconds, then 3 ticks of high damage every second for another 5 seconds.

Scenario 3:
I actually don’t remember whether new stacks cannot be applied at 25 or whether new stacks overwrite any stacks that have a lower duration, but the situation would be symmetric.

Scenario 4:
The effectiveness of regeneration ON a player is determined by the healing power of player it is on. So, if you apply regen to a player, it uses their healing power.