I plan to roleplay a hunter that will not do anything epic for a long time. Unfortunately every time my character hits lv 12 as soon as I open the 1st boss chest Meridia's Beacon pops out and hits me in the face starting the quest (or I simply don't pick it up if doing that quest wouldn't be in the character of my character lol). This time I wanna do it, but way later, and it's kinda stupid but I don't want the quest to hang on the list of my active quests. It's not really the most roleplaying move, but if I decide not to take it from the chest will I be able to get the quest later? What will happen to the beacon once the leveled list clears it out of the chest, can it spawn in another chest once I find the Shrine to Meridia?

Given the nature of the item in question, I'd assume that when the chest resets Meridia's Beacon will remain, as it is an essential item.

I believe Meridia will give you the quest if you go to her shrine. It should pop up again to find. TBH it should stay in the container...

I wondered that myself, as early on in my current game I found it in Bleak Falls Barrow, but didn't take it. I haven't been back there since, hoping that if I wanted to do the quest I could just go back and get it.

Might leave it for a while longer, then, if it doesn't reset.

My guess is that the beacon would disappear like any other item in a container when the container resets. I believe the 'essential' tag affects how an item behaves in our inventory (i.e. cannot drop) but not necessarily how an item behaves in a container.

If you leave it there long enough, it will simply appear in some other chest. I know this through experience.

Exactly, the "Quest Item" tag does not apply to containers and game world, only PC's inventory.

This is what I was hoping to hear, thanks!

That where it was recently for me.