Now that I'm at a PC instead of a tablet, let's start with my suggestion.
The POD are that Ulrika Eleonora fall down a bunch of stairs in 1710, this makes a potential coup against Charles Frederick of Schleswig-Holstein-Gottorp much harder. So he's crowned king (as Charles XIII) after Charles XII dies, this mean Swedish Absolutism continues. Sweden get pretty much the same peace, Charles XII likely lose Holstein-Gottorp also or he keep it and lose all of Swedish Pomerania[1], I lean toward Swedish Pomerania being kept.
After the War ends, Charles XIII begin to rebuild Sweden afterward, he likely marry someone else (I would suggest Princess Charlotte Amalie of Denmark), no idea what happens to russian succession, but I suspect Anna Petrona marry another minor German prince or duke. Charles XIII likely seek peace with Denmark, if he plans to regain the Baltic duchies that's necessary, of course later in his reign, he may end up seeing that's hopeless and a major target of Swedish expansion becomes Norway, but there lack a clear opportunity. In general he push higher domestic taxes to restablish the old army, but he likely also invest heavily in manufacturing and agricultural advances, invites foreigners to settle the empty forests etc.
The result being that Sweden by 1730 are able to field a significant army again (80.000 man seem pretty realistic), through still smaller than under the "Great Power Era". Charles XIII lives longer without travelling all around Europe, As the Austrian Succession War hit, France offer to fund a Swedish conflict with Russia. But Charles XIII look at a map and decides that it seems a pretty horrible idea. But there's another target, and Charles enter the war and invades Prussia, he makes a agreement with the Maria Theresa that she will allow him to gain all of Pomerania, the Saxons decides to go after East Prussia, as they can see that Prussia are suddenly the weak animal in the flock. The Swedish army entering the war in 1741 do in fact rival the army's size in the "Great Power Era"
Prussia end up losing Pomerania to the Swedes and Magdeburg, Kobutt and East Prussia to Saxony. Instead of Silesia, Austria lose Milan.
Sweden now have all of Pomerania, while not the greatest territory, it still have as 50-75% population as Norway or Finland, and it offer Sweden a large territory which the Swedish king can raise taxes without domestic protests. But it also remove Prussia as a factor in North Germany, which open the region up to a Swedish-Danish-Saxon rivalry. Charles XIII dies in 1749 leaving a adult but young son as new king. His son show himself a mediocre but competent king, and he continues his father reforms and expansion of army and navy. Sweden also begins to invest in colonial adventures, and buy a few sugar islands.
The Sweden leaving the Austrian Succession War I describe here are again a great power, it doesn't dominates as earlier, but it also have fewer enemies making ready to attack it. It's a Sweden where French, Austrian, Russian and British envoys negotiates for it to enter diufferent conflict. It have a significant army and it have four different paths to seek territorial expansion.
1: War with Denmark over Norway, but there's also a potentiale for a union.
2: War with Russia over the Baltic provinces.
3: Expansion in North Germany.
4: Partition of Poland.
[1]Sweden was allowed to keep a territory in Germany at the insistance of France, because they was co-guarantor of the Westphalian Peace, even if it was pretty much a joke at that point, but if Sweden lost that position, it would be harder for France to keep its.