It is kind of fun finding players with freak stats and hoping no one else notices so you can get them cheap.

I guess the question is how you decide what is ethical and what isn't, or is it just do anything to win?

Is starting a reliever who didn't start an ok thing to do for a final game of a playoff series?

Is it ok other times of the year?

Is it ok to use a player who played 2 innings at SS and 1300 innings at 3B but use him for 1302 innings at SS?

Who decides? If left up to each individual player, those who are more strict hurt their ability to compete.