Tidal locking for those of us who have to look it up How would such a construction affect the ocean tides? and also how would it affect the day night scale?

I can't claim to have any idea what a binary star system would do to a planet either, but it could be interesting to explore. I'm more interested in the tidal locking thing though. Both of these things open up the possibility of some enterprising soul to do a system map though so that's is kind of cool.

With the gunpowder/greek fire thing I think we are getting a bit too involved in the detail as this is unlikely to have significant effect on the maps whatever or not we go overboard. Besides the overboard things like a sea of fire (would be cool in any case in my opinion). There isn't so much to worry about. (guns though do have significant impact on maps)

Don't worry about sci-fi cross over Azelor. I'm telling you, everyone should read some of Jack Vance's Dying World stuff, it just has an absolutely inspiring texture and atmosphere to it. And it is pure fantasy but has such an underpinning of sci-fiedness to it you'll see that they fit together pretty seamlessly. In addition it has all sorts of wizards escaping to far off worlds, which when you consider the ideas brought up above could open up more mapping possibilities. Perhaps even allowing people freedom to make maps if they feel the constraints of the co-op world too heavy.