Have the Swedish Empire the largest it could possibly be, within a realistic perspective. I think that the Swedes have better planning in the Northern War and win at a Poltava-ese battle. They march on St. Petersburg and demoralize the Russians into a humiliating peace. What are your thoughts?
Your examples are from a rather late period. If Sweden instead gains a little more in the thirty years war (Mecklenburg, Hinterpommern). Succeeds with the Kedainia union with Lithuania in the 1650s but still fails temporarily in holding Poland, which leads to the Danish war, where Sweden instead of direct conquests might have coerced the Danes to join the Swedish realm in full but still have inner independence.
The 1670s war ends with the Swedish takeover of most of Brandenburg.
Now we have abolished butterflies and somehow get to Charles XII and the Great Northern War. Swedish forces conquer Poland and Saxony which are also joined with the Swedish crown. Russia will have to cede the Ukraine and the old Novgorod territories.
Since Swedish administration was comparably efficient at the time, this greater Sweden would have a reasonable chance for the future, and be an equal to France, Britain and Austria among the European great powers.