You have the 6-8 quests on the Peninsula you can do at any time. I think there's a total of 12 quests that the server randomly selects every day.
The Main Island has 3 daily quests + 3 that are connected to a specific mini-dungeon. You'll only have access to one mini-dungeon after a battle but the mini-dunegon quests are rotated after every battle.
I know I didn't explain very well but it basically means that you can do all 3 mini-dungeons if you re-visit TB after each battle. (assuming you win)
18 is the hiest, 6 from the north island + 12 from the south
when you are in control of the south island 2 npc's spawn with 3 quests each.
one of these npc's is always there but the other is random,
the random npc will give you 3 of 9 quests and can change upon each battle victory.
so the most badges you can get a day is 19 ( due to TANK giving 2)
3 fixed (Problim, croc hides, 12 alliance/horde) and 3 more that can be picked from 3 sets (totaling 9 possible quests). So 12 on the pvp island + 6 on the main island = 18 quests total.