I will make one completely new multiplayer mod for NW with new maps, units, new weapons with new stats (don't know about guns, they changed a little from Napoleonic times, and their changing demands a lot of coding, and I am not a scripter). As for new firearms - there will be revolvers as completely new weapons. British and French rifles (due to Minie bullets) and Russian, French, British and Turkish smoothbore muskets will have the same reloading time as smoothbore muskets in NW, Russian rifles will have the same reloading time as Baker rifles in NW, and as for accuracy - it will be the same or very slightly higher as in NW.
But also I'm planning to make a separate cosmetic mod for NW, to have both new uniforms and many players on server. But if there will be many bugs, like troops speaking not their language, or having wrong weapons or parts of uniforms - maybe I'll give up this cosmetic mod.
Also I hope after finishing the multiplayer mod (when all uniforms and weapons will be finished, and when there will be at least maps for Alma, Balaklava, Inkermann, Black river battles and last assault on Malakoff), I can finally start to work on the singleplayer mod for Warband.
Later I want to add maps to the multiplayer mod for other main events of the war: first bombardment of Sebastopol, assault on Eupathoria, fights for trenches near the old cemetery in front of the 5th Bastion, night assault on unfinished Volyn redoubt, assault on the Kamchatka lunette, first assault on Malakoff, different fights in trenches and rifle-pits, assaults on the 3rd, 4th, 5th Bastions in June 1855, assault on 2nd and 3rd Bastions in September 1855, siege of Silistra in 1853, siege of Petropavlovsk in 1854, maybe bombardment of Odessa in 1854 and maybe other maps)