i) The rulebook states that you should start with 5 tokens then shuffle the rest and replace another after each token has been placed on the board. But does it really matter? I mean can't you just choose either faceup or facedown all your tiles and pick among them? ii) Just for confirmation purpose, the figure swap token and the token swap token can only be used once and once only. correct? iii) Is the figure swap token necessary at all? I mean you could just swap the figures without ever need its presence there, right? (there's no proper place to place it anyway). thanks

Regarding #3, you only get to swap a figure if you have the swap token available to play (e.g. in your five-tile face up 'hand' hidden behind your screen). The swap token does NOT go on the board but is placed face-up in front of your screen after you've used it so that everyone knows it's been used and you don't accidentally do that action again.

It seems you may have some confusion about face up vs. face down tiles. You can only play tiles from your five-tile face up 'hand' of tiles that sits behind your screen. At the END of your turn (after you're done playing all tiles you will play that turn) you refresh your hand back up to 5 tiles by taking from your stack/pile of face down tiles and placing them face up behind your screen until you're at 5 face-up tiles.

At the end of the game, you may not be able to refresh your hand to 5; this is OK, you just refresh to whatever number of face-down un-used tiles are still available.