Funny thing is, without 'roids Bonds could have laid legit claim to greatest player ever....but he saw McGwire and Sosa doing it, and felt his legacy was somehow threatened and, ironically, probably destroyed his claim to GOAT (incidentally, I still say it is between him and Mays, 'roids or not).
It's interesting about the walks....when I came up with 150-200 less homeruns, that was a projected trend (based on how almost every athlete declines, particularly in baseball) from where he was in '99 when he started....but if he had 1000 more walks he probably would have hit 60-80 home runs instead, so maybe we are talking in the ballpark of 650.
Also, I always kind of thought nagging injuries were a sign of steroid use - helps you recover but also makes you more susceptible to injury.