The fact that all your cities aren't connected is making me want to take over your file and do that. Like I'll build roads to things before I actually build the improvements, because it's logical man - which is one of my problems with Civ V; roads aren't something you get right away.
And your play-style is quite... passive, as you said. Early in the game I usually focus on science and building cities near important resources and then building my military as I begin meeting new rivals. I also usually have cultural **** going in the background at all times - having half of another nation's cities overthrow their evil masters and join your empire is an awesome feeling.
Also you should use a lot of spies, they're cool guys.