3. We already have "Ancient Ballistics" I do not think we should have one called "Ballistics" it should be a different name or move "Ancient Ballistics" back.
There were two type of Ballistics; Stationary and Mobile. You are both correct. In the Bronze Age it was customary to use Ballistic Weapons that were portable, miniture versions, and you had to set up to use. In the Iron Age they became mobile with wheels and had required two individuals needed to operate them. In the Medieval Age, they became quite specialized and gigantic.
Here is an example of a Bronze Age artillery. Notice it has no wheels, and it had to be set up.
Portable.
Greek
Roman
Here is an example of Iron Age artillery, noticed it has a different configuration and it has wheels.
This is an example of Medieval Age artilley, notice it became alot bigger in size, and lost its wheels.
The same happened with Mangonel, Onager, the ballista, and the traction trebuchet .
I would recommend two Ballistic technologies, and move Seige Warfare to the far Classical.
The first needs to be placed around Military Training and called Ballstics or Artillery. You can include the Crossbow in this technology too.
Ancient Ballistics needs to be placed after Machienery and renamed to Siege Engine. The reason is that the next leap foward in Siege technology occured with machinery.
Siege Warfare needs to be placed after Surveying and Invention. It can keep its name, I perfer Siege Engineering.
Artillery could be renamed Field Artillery so that its ancient version could have the name Artillery.
On another note, I like the Tech Tree HydromancerX proposed a post or two above. I would have liked if there was a Mathmatical technology called Equations or Decimals around x23, but Standarlization is a good replacement for that.
Also of note, I noticed you had Monarchy in Ancient Era,(I am assuming because of Persia). I would recommend you think about having a Dynasty or Mandate of Heaven technology in Classical that represents the East.
Also, Astronomy and Cosmology need to be included in Classical, and Astronomy renamed to Applied Astronomy and Cosmology to Applied Cosmology. The reasoning is that there should be,(if not already), a technology in Classical, Medieval, and Renassiance that represent the work in that field at that time period.
You sohuld have a Culinary Arts tech in Renassiance to represent the standarlization of cooking by the Frech, and the first academy of cusine. You can include seveal fruits, vegestables, and legumes that were discovered in the New World during the Age of Discovery.