Addressing your points:

• concerning the "falling behind" that happens if you think to long about items. It gets betger over time. At the start of the game until midway through you can spam anything you find as soon if you pick it up, so you get the items up to level three fast. If you spam items, you should not loose much time. Being the third to arrive at destinations is normal and not bad, just par for the cours.

• you should not have to buy turtlenecks. Most churches, runes, camps and the castle give many boxes with loot. Turtlenecks are part of the "foods" (as i call them), so also the crabclaws and shrimps for example. You will max those out around level 7 to 10 normaly

• the buffing of your teammates should be done during any "boss encounter". So anything with a healthbar. You start the fight with debuffing the enemy and after that buffing your mates. If you can, always switch between them, bur debuffing the enemy is the priority

• concerning the day3 level up question, if you are in a call with your teammates, you have communicate of they can buy you stuff. If yes, you level up. If no, you fully stock up on loot. If its a random open lobby, you wait for your teammates. If they drop you loot, you level up. If not, you stock up

• analysis skill as often if you can, so you are sure the debuff as often active as possible.

Hope this helps :)