When I stack Flavor tokens on the right side of the board, are the following statements correct?
* I can only stack exactly 2 and not more
Yes, why would you want to stack more (see text below)?
* The top token determines the allowed spots according to normal rules
* The tokens can be of same type or different types
Yes, it's not stated otherwise.
* The ability of neither of those tokens can be used, i.e. this action ONLY lets me get rid of the tokens
Yes. You get rid of them, so they can't pop up during the cup test AND they let you work on the bonus tile on the right side which is important!
* I can never slide a token under a previously placed token to get rid of it
Also I don't quite understand why I would want to do that. Extra Flavor tokens mean more actions in future turns and also no penalty in the cup test. What would be a reason to get rid of Flavor tokens without using their ability?
On the one hand you should not get rid of the tokens - because you know how many there are in the pool and you need some in the cup test and you want to keep the probability high to draw one. On the other hand, it's bad to draw 2 or more of one kind of flavor token in the cup test, so you have to think twice about that.
You can get rid of those on the left side of the board or on the right sight. The difference is, that you have to meet at prerequisite to do that for the right side, so it's more difficult. If you can't meet the prerequisite (split a bean or combine two beans..) you can't place it there, unless you place two of them. In my games, I want to place it on the right side but can't split two beans, then I "sacrifice" two tokens in order to place it there, so I only need one other token to get a bonus tile from the right side. But I don't use this action that often.
It's hard to explain, but there are situations where you NEED the sweetness token in your last turn but you don't want to split beans for example.