Workers can already build fortresses, and a line of them is somewhat like a wall. It's be neat if the graphics respresented that, and connected any two fotresses bult in adjacent squares by a wall. Sure, the Great Wall of China is a Wonder, but that's not the only historical example of a wall (Hadrian's Wall in between Roman England and Scotland, or the "security fence" going up in modern Israel, to throw out two examples off the top of my head). One-man-assault's worry about exploits wouldn't be an issue if it was merely a graphical change related to building fortresses (since fortresses are already in the game).
A more friendly editor is of course a good idea.
I'm not sure what is meant in the poll by "better modern units".
I must admit I don't see the point of a transport plane. Is this request a gameplay issue or a realism issue? Its certainly not very realistic to be able to airdrop entire units of modern armor, etc. Just witness the Iraq war: the US was prevented from having a major northern front because Turkey didn't cooperate and let the US unload in Turkish ports. A number of troops were airdropped into Northern Iraq, but bringing in a major force of heavy vehicles by air was not feasible. It takes an entire plane to transport a single Abrams tank... so, while its possible on a small scale, its not realistic to move entire companies/battalions/divisions/whatever on the strategic scale representing combat in Civ. If its a gameplay-related request, I also don't really understand, since not being able to airdrop certain units encourages the use of other units, which IMHO is a good thing because otherwise modern armor would be the only thing anyone every built in the modern age. I think combined arms should be encouraged more, and I'm afraid transport planes that let you move modern armor around willy-nilly would discourage combined arms. All you'd ever need for modern war would be oodles of modern armor and transports.