Have you thought about adding in new units to the tech tree? That's one of the 3 things I'd want to add. Units between Crossbows and Gatlings, between Frigates and BShips, and maaaybe something between Knight and Cavalry. Plus something to fix the lancer weirdness, and in my dreams a light cavalry line. This works with the Enlightenment theme.
Currently I am planning changes to the technology tree and balancing that.
To be honest I think I have more ideas than we can include in this pack - for example 20 new units...
MY IDEAS
Galley - Trireme - Galleas - Caravel/
Galleon - Frigate/Privateer
Musketman -
Line Infantry - Rifleman
Trebuchet -
Culverin - Field Artillery - Artillery
Lancer -
Dragoon - Cavalry -
Modern Cavalry
Crossbowman -
Grenadier - Gatling Gun
Scout - Adventurer - Explorer -
Sniper -
Special Forces
Reasons for each unit:
Galley - some changes need to be made with early naval warfare to make early naval units more useful...
Galleon - I don't like the total domination of Navigation tech, Frigates should have alternatives
[generally speaking I think that ships should work as rock - paper - scissors, this seems to be necessary to make naval warfare - lacking terrain and cities - more tactical]
Line Infantry - XVIII century infantry
Culverin - Renaissance early cannon, 3d model of current Cannon
Field Artillery - XVIII/XIX century mobile cannon, 3d model of civil war cannons
Dragoon - I don't like that Knights are Knights for the entire renaissance while trebuchets, pikemen and swordsmen are upgraded soon...
Modern Cavalry - cavalry was widely used until WWII, I would like to put MC between cavalry and landships
Grenadier - I don't like that Crossbowmen are forced to fight with Musketmen/Cannons/Lancers till Gatling Gun, this is IMHO unfair. Also grenadiers are cool.
Adventurer [late medieval] and Explorer [industrial] are obvious exploration units which have many mods
Sniper - WWI/WWII far range unit
Special Forces - special unit with very awesome abilities and the finisher of the Recon line, maybe replacing completely useless Marine
Currently I am working on some kind of plan of Enlightment era techs [and my own General Coherent Vision of Expansion]
EDIT
Also JFD and TPangolin - what would you say about this Alternate Research System:
all techs are divided between categories: Army - Navy - Economy - Intellect
you choose which of these categories your civ focuses on currently ['Our Government invests in new minds seeking military solutions']
then random technology is chosen [based on probability, includes few factors like 'there is a chance for discovering gunpowder immediately in medieval but you will rather get construction']
(obviously 'random technology' means the
closest techs from particular focus so you won't get nuclear physics in ancient era)
and starts researching... You don't see the progress of this technology once you choose Focus! This adds the element of risk - 'aww I still get no tech, maybe change focus? but what if some genius is researching very valuable technology and he just needs time?'
Alternative solution, if unability to see the tech progress would be frustrating - player can see PERCENTAGE progress of tech but he still doesn't know what exactly his Einstein is working on ['I am the king not nerd, what does it mean 'quantum conundrum' and can we used to get rid of these pesky Zulu?! Aww we will see, I trust my national nerds']
This is way more realistic - ruler of the empire doesn't say 'we need nukes - hey you scientists, let's research new revolutionary idea!' but 'we need Wunderwaffe, let's focus the empire on particular section of knowledge' and then he awaits on results of great minds working somewhere in universities and laboratories... Which of course need to be built and supported by the state.