Why is there no buttobi?
There are many reasons and most important being not wanting the duration taken to complete a han-chan to fluctuate too much. A premature ending causes imbalance to score recording. As each player plays and pay by 2 hour game, to have a premature ended han-chan and an incomplete han-chan is a rather undesirable result to the majority players.
Who get the Honba points or riichi sticks deposit in an event of multiple ron?
The next player in turn to get both Riichi sticks and Honba points in any situation of multiple rons
What is the procedure when you get Kyuushukyuuhai (九種九牌) ?
Reveal the 9 tiles (even if you have more than 9) will do. While there is no penalty if one reveal his whole hand, just make it a good habit to show only the 9 tiles. This is to be on the safe side to avoid potential chombo situation argument.
What happens if I have forgotten to separate my tsumo tile when I declare a tsumo win?
Players who fail to do so will only claim for lowest possible fan/fu. This means that if you are able to claim for 2 fan 20 fu for pinfu + tsumo but because there is no proof what kind of wait you have had, it will result to 1fan 30fu, menzen tsumo only.
Does a han-chan automatically ends if the dealer complete last round and emerge as 1st place?
No. Under the Agari-yame Nashi rule, the han-chan will continue reguardless of position.
Can Kokushii Musou Ron on an Ankan?
Adding on as we go on.