And there were Swedish merchant seamen who have participated in WWII de facto - being under danger of naval and air attacks from all sides in all seas, from Baltic to South Atlantic. Losses were in hundreds...

Indeed there were, dimlee! A lot of Swedish merchant ships sailed with supplies between North America and the British isles and several were sunk by the U-boats.
Some of the surviving sailers were so pissed off at the Germans they joined the Allied Forces after beeing sunk. Sivert Windh from Hässleholm, Sweden were I live was one of them. He joined the US Army after beeing his ship had been sunk. He fought ass an infantry man from Normandy to the Ardennes were he was wounded. He was then transfered to the SOE and ended the War on a mission in northern Norway after beeing accidentaly dropped on the wrong side of the border by a C-47 with his team. They ended up on the Swedish side of the Mountains and stumbled upon a Swedish policeman who thought they were spies and arrested them. The policeman was quite surprised when Sivert spoke to him in perfekt Swedish with our typical Scanian dialect. He and his team was later released to continue their mission into Norway.

A map of the Southern Baltic Sea with Denmark in the western southern Sweden in the middle, the Baltic coast in the east and the German/Polish coast in the south would fit well then.
It would be great for Allied bombing and anti-shipping mission in the area, the German defence of course and both sides ended up over southern sweden on several occasions. Just outside Hässleholm here in southern Sweden were I live a British Lancaster was shot down by a German Ju 88 night fighter stationed in Denmark in 1944 during a bombing mission against Königsberg for example. So a map like that would be ver interesting and usable to have. I doubt there will ever be any Swedish built fighters introduced to the stock game but we already have the J8A Gladiator, the Falco CR.42 and the Re.2000 that was used by the Swedish Airforce at the time.

I believe that there is a map of the German/Polish coast around Danzig/Gdansk in the works, but I don't know if it's a mod or will be an official release.

There is a modded map of Denmark which is little more than just the geographic map - few towns, no roads or railroads.

The problem with maps of Western and Northern Europe are that that they're densely settled places, with lots of buildings, roads, railroads, and canals. That limits the effective map size unless you want to wait 20 minutes for the map to load, or slow the game to a crawl if you get into a big dogfight over a major city.

My guess is that at best, maps of such areas could be 150 km square, possibly less - about the size of the Berlin map.

From the point of view of Allied bombing ops, especially RAF missions, a map of Schleswig-Holstein, starting at the Danish border, and covering the cities of Flensburg, Kiel, Hamburg, Bremerhaven, Cuxhaven, and Wilhelmshaven would make the most sense for a "Northern Germany" map.

Notable targets would be U-boat pens and production facilities at Kiel and Bremerhaven, as well as the Kiel ship canal, and various industrial areas of Hamburg. The harbor between Bremerhaven and Wilhelmshaven, and the coastal areas, lend themselves to mine-laying missions.

Another potentially interesting map, albeit for areas that didn't see as much action, would be from Rostock to Swinemunde/Świnoujście, taking in the islands of Wolin & Usedom/Uznam, then up to Copenhagen and Malmo.

The notable target in this area is, of course, Peenemeunde, as well as industrial areas of Rostock and Copenhagen. This map could potentially be bigger because there's a lot of water.

What I had in mind would be a map with mostly water in this case with only a thinner coastal area present for Denmark, Germany and the baltic side to the west, south and east. The only bigger landmass would be Skåne portruding from the north.

These map ideas would be quite interesting. But there is a problem. Important planes are missing: Flyable Ju-88C6, and flyable early Beaufighter variants, like the Mk.VI. Both are direly needed elsewhere too... :(

Agreed!