Germany could have won the war up to and including the battle of Kursk
If Stalin could have been made to sue for peace or effectively marginalized - which, again, I believe would have been possible but not likely in '43
The best Germany could ever hope for by Kursk, was a stalemate. I would like to see some sort of plan that even remotely gives them a chance to win, by that time......

Allied performance in North Africa, Normandy, Italy, Market Garden, and the Battle of the Bulge strongly suggests that they would not have fared well against first-line German military units
A rather harsh and decidedly untrue statement. The Eastern Front, while it certainly attracted a much higher total number of German units, doesn't automatically qualify that theatre of operations as having the 'vast majority' of first-line units.