Okay, so, if I understood well, it's the same skirmish battles as the basic games.    How are they called ? Otherwise, I'll start to develop my mod the next week ! I chose to name it "Elpis" : Elpis is the personification of hope in the Greek mythology...

Changing unit speeds and giving units more specialized roles. This is made quite difficult by citizen soldiers, and by unit availability by civ, but i believe it is possible. 

The historical reason for missiles not dominating is friendly-fire. One should not be able or willing to fire missile in a melee due to fear of hitting own units. Missiles should be for skirmishing and harassing.

Technically at some point someone planned for walls to upgrade to fortresses.

Since 0ad is a historically-themed (if not historically realist) game, the way missile work as of now (being the main weapon) is really bad and harming the gameplay a lot. What are the solutions ? What is the role that we want for missiles and how to do it right ?