you could combine the US and UK rank insignias in a similar way to this.
If they are meant to be used on miniatures, you could otherwise start with the idea of insignias being discernible on ~ 28mm figure so that, for example, officers all have red gorget patch and accessories tells ranks...
Just to get pedantic, those are not "flags of France", they are banners of arms meant to represent the *king* of France.
The reason I point this out is that, like many other monarchies at the time, the french used a number of flags and which one would end up being a "National Flag"
might vary...
Simplest way I can think of is to with OTL New Amsterdam (ex: southern part of OTL Manhattan) and then extending from there in a different direction than OTL NYC (ex: the rest of OTL Manhattan then up the peninsula to include OTL Queens, Yonkers, MT Vernon, Pelham & Pelham Manor.)
Smaller towns...
Maybe something computer related like I/0 symbol or something inspired by printed circuits.
For example, I did this for a cyberpunk USA some years ago:
That's the OTL "Ancien Régime" COA of the late 18th century. It wasn't used during the Restoration Era despite going back to a monarchical Kingdom following the 1st Republic, Directorate, Consulate and Napoleonic Imperial era.
The Reason I mention this is that it would seem to imply either that...
Not sure what you mean. What is your definition of "Australasia" (there are more than one definitions) ? Are you asking to join North America and "Australasia" together as a single geographical entity ? What borders are meant to be used by "Australasia" ?
what's the definition of "major languages" ? French is spoken by 20 percent of Canadians but is official at the federal level, is the dominant language in the province of Quebec and the language spoken by 1/3 of people in New Brunswick where is it protected as "co-equal" with english. Not trying...
bear in mind that some region have mixed linguistic communities. The Brussels Capital Region in Belgium is a good example. Waloonia is mainly French speaking and Flanders is mainly dutch speaking but Brussels is a mixed bag.