Ok so yes it is possible however I'm not sure it is always possible. A lot of things can go wrong and you don't have a great deal of control over lots of it. the AI seem better at conquering on epic and snowballs even harder. The bonuses from conquering scale up so they had absurd amounts of gold and science from it.
If everyone is peaceful other than bashing you then you can sit back and tech up fairly safely. but at the other end if one player takes over the whole world you can't win before they do something to win. That said you only really need one players to buy techs off, and you can still steal from hostile players.
I won on t501 and was almost killed by nukes because I thought I passed nuclear non proliferation but didn't. I think with it you can hold off the AI pretty much forever. I don't see how you win anything other than a science victory but the AI isn't great at winning at all so you have a reasonable amount of time as long as you don't die.
If everyone is peaceful other than bashing you then you can sit back and tech up fairly safely. but at the other end if one player takes over the whole world you can't win before they do something to win. That said you only really need one players to buy techs off, and you can still steal from hostile players.
I won on t501 and was almost killed by nukes because I thought I passed nuclear non proliferation but didn't. I think with it you can hold off the AI pretty much forever. I don't see how you win anything other than a science victory but the AI isn't great at winning at all so you have a reasonable amount of time as long as you don't die.