I think you're confused by a few things, here. SYORTD is a tool used in games where the GM is discouraged from negating properly formed action declarations by players. Proper formed here means within the genre and theme of the gane, so no finding a laser pistol in an Aurthurian Legends game. SYORTD then simply means that you allow the action (say yes) or that you use the gane mechanics to determine the outcome (or roll the dice).
That said, here's my specific issues:
One, there's no requirement for SYORTD to not include fiction creation. The secret door example shows this. If a player declares the look for a secret door, in SYORTD they either find one (yes) or they get a test where a success means they find one (or roll the dice). This is an action declaration that includes fiction creation and SYORTD works swimmingly for it.
As for your DW example, you just say you can't say yes. But, you most definitely can, and that's perfectly within the rules. What you seem to be confusing is that GM advice for DW is to drive conflict, so unless the request is trivial you probably should involve tge dice so the cire gane engine of generating chaos can work. But that's advice on when to ORTD, not to never SY.
In DW there's no roll to be made for new content intro by Pcs. The Gm decides and that's it.
Yes, this is different and not related to SYORTD.
No, because here there's no SYORTD going on, there's a prescripted encounter where Yes is already approved if the players choose to parley. The GM can say no if the players choose an unscripted action, like, say, searching for a secret door where the map key says none exist. SYORTD is a universal GM tool, not one that works so long as the GM prep says it does. In fact, SYORTD really doesn't function in games with heavy GM prep or with prepared modules at all. It works very well in low/no myth games with fiction introduction by players. Which is no surprise, as this kind of game is where SYORTD came to maturity as a GM tool.