What if Gensokyo gets personified in Hetalia?
Gensokyo would be portrayed as a cheerful, energetic young girl who locks herself in her room and marvels at anything that blows in through the window.
I thought of a longer, more detailed response to a question I answered a few rounds back.
What if ZUN decided to open source his games?
Development of Open Touhou would fracture into two groups: Those who would loyally follow ZUN for all he's done for the series so far, and those who would see him a dictator for his strict creative control. After an fearsome flame war, the groups would part ways and the latter of the two would develop a fork called YITIYARNS (an acronym for "YITIYARNS Isn't Touhou It's Yet Another Recursively-Named Shooter"). YITIYARNS would run on GNU/Linux, Unix, Mac OS X, BSD, and Amiga OS, with a third-party port for Windows. The KDE build would be named Kouhou. YITIYARNS would use twice the resources of Open Touhou, but the bug report would be closed as "will not fix" because the problem would actually be caused by a shortcoming in Qt.
Due to nuances in trademark law, YITIYARNS wouldn't be able to use Open Touhou's artwork. The sprite format would be backwards compatible, but using OT's data files may be illegal in your jurisdiction (contact your lawyer before installing). To work around this, YITIYARNS 0.1.6 would star ReiGNU, a generic "anime" girl with a penguin T-shirt and ten shot types. The bosses would be based on Microsoft products that had become fantasy through obsolescence (Wingdows 3milia Scarlet). These characters would be intended to be temporary stand-ins, but YITIYARNS would never really find a skilled enough character designer to replace them.
YITIYARNS 3.0 Beta would be incompatible with previous versions, but would include a new playable character named Hurdmima, as well as a built-in web browser for automatically downloading and installing fan-made stages. Unfortunately, years would pass without the release of a stable version. As for Open Touhou itself, it would soon be superseded by a closed-source rewrite.
What if Touhou gained mainstream recognition and praise because of a fighter, while the shooters remained relatively obscure?