I want to make use of the 100% bonus this week and I have a question
does it stack WITH the War Mode 25% bonus for quests?
and Also, I have heirlooms capped for 110 (upgrade 3/4)
do I still get EXP bonus from them (30% for head, chest, legs)
and do they ALSO stack with the War Mode and Event 100% Bonus?
Heirlooms does not give exp after their current upgrade, in your case it wont work in the range 110-120. You will need to upgrade those heirlooms to 4/4
I am not sure about party sync but heirlooms were nerfed for Timewalking so your real level is what determines if heirlooms work or not instead of the reduced level for TW dungeons.