The station being visible behind the station menu is nice, but I suggest it's changed (again).

My suggestion is that the current menu is removed and replaced by viewing the inside of the station. All complete with different doors out to hangars and into different shops.

The whole mall would be populated by pre-animated non-interactive models doing whatever and walking around. The player would observe it through a fixed-angle camera.

This would also allow a station to have no "Mining post" store, and thus provides no purchase or sales of basic minerals.
Maybe they instead have a luxuary shop that buys rare minerals, civilian textiles etc and sells luxuary items?

This is how I think a station should work when docked:

The player is presented with a screen that looks like a snapshot of a mall (or whatever is apropriate for the station).
On the top of the screen the available choises for the station (Ships, guns, machine shop, return to hangar, bar and UIT Office in this case) are shown.
It does not even need to be 3D. Infact I think it would be more suitable for 2D since only one side of everything is viewed anyway.

When the mouse is over a door that door opens up and the approriate item on the top is highlited. Just clicking them directly on the top of the screen does the same thing as clicking the (now open) door.

Similarly, hovering the mouse over the menu items on the top would open the apropriate door.

Then (s)he clicks the store that has a model of a Maud on display in the window. The "Buy ship" dialog, more or less exacly as it is now, appears. The user selects and buys a ship in the now-in-place way.

Upon buying the ship the player is returned to the mall snapshot thing.
(S)He then clicks the store displaying a Gauss gun in the window and the "Buy" menu comes up, but only weapons are available.
The player buys a gauss gun to go with the cent (s)he just bought and clicks OK. View returns to the mall.
(S)He then clicks the store with a wrench over it's door and a guy messing with an engine visible throgh the window.
This brings up the "Ship" menu and the "Weapons groups" dialogs.

After making sure the battery and gun are in place in the ship the player clicks the door with the UIT logo on it to see the local UIT offical staff. This gives access to missions, the faction standings interface and stuff like that.
After signing up to bring back a datapad from some other station the player goes into the bar to check local news and chat for a while.
When the player is done (s)he walks off to the hangar again.

The whole 3D-rendered station thing can be optional, ofcourse, since the buttons up top would also work to do the exact same things.

So what's the point? Won't it just make navigation in the stations more complicated?

No. Not more complicated than the change from no background to 3D station background.
It will add immersion to the game and the possibility for the devs to make each station as unique as they want. Ofcourse the inside would be exacly the same for all stations until they have time to tweak each one to become an indevidual station, but when the system itself of an iternal representation of the commercial deck of a station is in place there is no end to the modularity and visual imersion.

It would make stations feel like a real place and not like somwhere you dock and it jacks into the ships menu system without the pilot ever leaving the craft.

Please DO NOT comfuse this with "First person walking around the station". Think like the stations in Freespace and games like that.

Speaking as someone who plays the game occasionally on a 4MB video card... we do not need low framerates inside the stations. I already only get about 20fps.
If this feature is added, add it as an option only. Not like the new targeting heuristic.
-:sigma.SB