If you are constantly winning on Monarch on all map sizes, you should make the move to Emperor. When I first played Emperor, I was annoyed because the AI has so many more units in the very early game, that are just bonus units. I once saw a small stack of three spearmen and two warriors march by looking for barbarians, while I was just producing my second warrior in my only city. One suggestion I have is to play your first game at Emperor level on a small map. This makes the game much easier than on larger maps. It may also be easier on larger maps with fewer civs, but I always play with the max amount of civs for the map size.
In my opinion, you will have to go to war at some point to expand your territory, unless you had some really outstanding and unusual situation in the early game that allowed you to grab a lot of land. At Emperor and Diety levels, the AI can produce settlers at a very fast rate.
I usually expand as far as I can, and build a cheap temple (Egyptian) in every city to secure the culture (The AI is much better at buliding culture at this level). I research iron working and go to war as soon as I have a pile of twelve to twenty swordsmen, depending on the surrounding civs and the geographic situation. I don't worry too much about building wonders until the industrial age - I usually end up capturing a few that are beneficial like Sistine Chapel. The wonders that I really like to have are Theory of Evolution, Hoover Dam and United Nations.
While at war, I will research to Monarchy and change governments. I usually then put research at 0% and buy techs with money, or force them with a peace treaty. I change this later on when my civ is developed. Not researching my own techs also gives me the cash to rush temples in my newly aquired cities. I build Forbidden Palace as soon as possible, but always make sure to put it in a favorable location where I can get the most benefit as possible. As soon as my kingdom is at a size for maximum production, I build culture and science like crazy. It is common for me to be at the top of the histograph by the Industrial age at the latest, unless there is some rampaging civ on another continent destroying other civs.
I usually win by space race or diplomacy. On some games I disable certain victory conditions like space race to make the game longer or different. I usually don't win by conquering the entire map, but have before. So in answer to your building stategy question, I think that being a builder at Emporer level is an option, as long as you are willing to do a little warring in the early game.
