Idea: Have the bot move to an item always - even if that item is picked up by another player (meaning your character doesn't move or only moves halfway towards the item). If a drop party is going on, then the items generally will be placed near each other. By having the character continue to move towards the path of the dropped items, instead of staying in place, you would have a greater chance of grabbing other items that are being dropped in that area.
Also, if possible, could you add the item coords in the logger for future debugging with web walker? There are many areas where web walker gets stuck (i.e. around GE tree spirit, far SW corner of GE).