Guys like Lafleur, Perreault and Dionne were allowed to play 'their game' in the 70's. None of them were expected to be physical and fight because those roles were filled by their teammates. Gretzky would have been able to do the same, and being more more talented than those three would have beat them in the scoring title races about as handily as he buried the competition until Lemieux came around. Whether he gets the MVP's and 200pt seasons would largely be based on the team he ends up on, but IMO he beat's Espo, Lafluer and Dionne's best scoring seasons handily just like he did in the 80's.
Maybe the others on your list, but no way is he lapping Espo like the others. I'm not saying Gretzky wouldn't win the Art Ross, but not over the same % as he did in the eighties. He would have to DOUBLE his production.
Why? Because Espo actually scored AT A HIGHER % over his positional peers than even Gretzky did in the eighties.
When looking at the top percentage leaders over their positional peers (using adjusted stats) from the center position, Gretzky holds 2 of the top four spots, but Esposito holds the top spot overall:
1) Esposito Phil 1970-71 147 pts 79.27%
Ullman Norm 1970-71 82 pts
2) Gretzky Wayne 1983-84 164 pts 72.63%
Stastny Peter 1983-84 95 pts
3) Gretzky Wayne 1986-87 157 pts 70.65%
Lemieux Mario 1986-87 92 pts
4) Esposito Phil 1973-74 135 pts 66.67%
Clarke Bobby 1973-74 81 pts
Of course, if you flip Espo with Gretzky, then all bets would be off, as Orr would be feeding Gretzky and vice versa...