There is a loop to cheese levels. Went from 30 something to max in a couple hours.

Limited time quest and level cap increased to 120 update is live. The quest you have to kill 100 cactuars in a specific area. Get a lot of AP and gil for it. Expansion will be in a couple weeks.

Wait so is te level cap only increased for a limited time?

No level cap is permanent. Just the quest is limited time.

So by doing the cactuar quest i should get the cactuar needle easily to upgrade the crossbow ( or whatever the weap that need the item from cactuar)?

You could. But you can find them in the world. Just Google it and there will be one or 2 easy spots you can find one really quick.

did the event was fun n rewarding but didnt get a single cactuar needle

Episode gladios was pretty fun. Short but loved the combat and the added trophies were pretty easy to get. Episode prompto out in June. There will be other timed hunts and quests added randomly.

Did it add a lot to the story?

Just started playing the game. Any advice in terms of what I should keep and sell in treasures? I feel like some of them will have a great impact in elemency later on, but I also need gil for items and weapons.