i think there shuld be alot more techs in the modern age as well. i like the ideas listed.
my thoughts.
why can a horsearcher move as much a tank?
why not add the ability to refuel in the air?
add different aircraft options, each enabled by a different tech.
and yes, since a marine can not travel 600 miles in a day with out a transport, add land transports.
add units to do the air transporting instead of clicking a button and *POOF* the unit is in the city.
and yes, add a modern method of increasing movement.
i like adding some type of global warming guage.
i remember in civ2 i could build caravans. i know now i can get a great merchant, but i would like to build the caravan unit, freight, or what ever. it doesn't have to give as much gold as a GM, and not add to a trade route, just be a sale of goods.
a prereq's to computers like microprocessor and supeconductor.
add techs to the modern era which enable something unique; like a unit and or a building.
in the modern era we don't just have a university. the little community college in my hometown is not the same as a yale or harvard. modern era should reflect different types of schools.
i just don't think you should have more or equal techs and units in ancient era than you would in the modern era. there are a lot of builders out there.