My main suggestions for event mostly towards the dungeon aspect part: Just make the cooldown 5mins instead of 10, would make someone like me that spent time getting 1500 tickets to be able go into dungeon faster to get necessary parts for what I desire.
Make the amount of Zombies 20 of each that way you can do the daily quest in at least 1 run, and prob make the boss spawn after they all killed since some people are/were confused it spawned after few kills.
The SL skull/ribs dont bother me since Im going try farm the dungeon more since thts only real way to get the arms an legs unless you buy from others.
Maybe make the coffees little cheaper the First 2 reduce those to 20 of those QI, then the 3rd one 15 of each arm/legs that way your not wasting to much of skull/ribs especially if your doing dungeon mainly.
I do agree alot of the stuff thats SL in the boxes does suck since you might get something you rather have on different character or you dont need at all. Some I understand, just there are people that don't just farm for themselves they farm to sell and if items cant be sold then people are forced to farm themselves or not buy/farm at all then people don't get on for the event and the game suffers some from no players active.