No, you can't. Just think...
You set a chest to randomly go from 1-35 variable items
Then then you can get a number such as 1,2,3,4......33,34,35.
If the number that you get is 20, and the items that you set on the chest is only from 1-8...You won't get anything...That's your problem as far as i see...
To fix that, where you set the ITEMS range to each chest, simply change it from the numbers you want to...
1st chest: 1-8
make a condition to 1-8 number.
2nd chest: 9-17
make a condition to 9-17 number.
That will make your problem solved, and you will always get an item, and you don't need all the conditions of all numbers in all the chests...
About the sound...It must have come with this problem too...
"I added the chest opening sound effect, but it dont play on everytime I open the chest, but I have it under every conditional branch"
If you don't have all the condition branches to all the item variable numbers, ofc you won't get an item, and the sound, so...
Fix the numbers, and the ranges, and put a sound effect in the beginning of the event. It will work for sure!