Going back to the topic the thread was started around, yes, I would like a new "Imperial" era. Also, over the musketman/rifleman issue, perhaps this could be solved by adding a new unit. The new unit would be a balance between rifles/muskets with maybe 20 or so strength and unlocking with cannons. It would be called something like "Line Infantry".
The historicality (if that is a word) behind this would be that it is after the early musketman already seen but before the rifled muskets used in the American Civil War. This would be what was used around the time of Napoleon.
I would like the following 'gunpowder' unit line-up:
Arquebusier (gunpowder)
Musketmen (Matchlock)
Line Infantry (Flintlock + bayonette)
Riflemen (Rifling)
I think you are right to include line infantry. Hopefully the tech tree is expanded enough so that they can be included. Also, welcome to the forums!