Sue's advice is excellent for adding your own clouds.

If you might be interested in using symbols instead - or as well as - you may like to see the Alyssa Faden style pack, which was part of the Cartographer's Annual in 2014, as that comes with a number of cloud symbols designed specifically for use on overland maps.

If you find you've placed a door the wrong way after it's cut the wall, you can simply move the door symbol so it's the way you need it.

You can also turn off the Smart Tracking by clicking the check box in the Symbol Parameters pane (right click when you have the symbol on your cursor). This will stop the door aligning to the wall whichever way it wants (which may cause problems if you're trying to get the door properly aligned with the wall, however). It will still cut the wall as normal, while you have control over how the door is placed.

If you click the Disable Smart Symbols box, that will stop the door from cutting the wall at all.

This applies to all the Smart Tracking wall-cutting symbols, incidentally not just the doors.

This is the link for the Cartographer's Annual issue JimP mentioned, although as you'll see, that's intended primarily for drawing a randomly-created night sky as seen from a specific planet.

However, you could use the same procedure as in that Annual issue to construct a random basis for your galactic-scale star systems map. That was done using the Symbols In Area command. Resident mapping expert here Remy Monsen presented this as the last of his 52-week Command of the Week series of written tutorials that ran throughout 2017. You can find that article on the Forum here.

Of course, all that would do would be to place an appropriate number and type of symbol randomly over whatever area of your map you'd chosen. It would then be up to you to decide what the details were for each system (though by using different symbols, and assigning types of detail for each symbol on a separate key list, you could make a start on that process).

Symbols In Area is a useful tool in many respects, because you can vary all the random parameters as much as you like, and by drawing different areas, you can add different populations of symbols to different places. For instance, if you wanted a greater density of star systems in one place than another - along a galactic arm, say - you could just draw a suitable polygon shape wherever you wanted the arm to be, and then add a selection (or selections) of symbols to that area alone.

From the way you've done this, and your comments, I'm guessing this was originally a hex map with just the classic one symbol per hex, and that those hexes equate with the over-sized hexes you're mapping now. Are the "chicken-wire" smaller hexes part of the remit for this map? I know why they're probably there, if following the classic D&D/Judges Guild fashion, but maybe they could be toned-down a little for this one? They're a bit too distracting right now, especially with the empty expanses of sandy desert.

You could maybe add some wadi lines, scattered small rocks, even small patches of greenery (the rare desert rainstorms cause a rapid abundance of growth with many bright flowers for a short period, for instance) to help break-up the barren flatness of it all otherwise. And maybe try hiding the hex grid entirely while you do so, to avoid unconsciously following the hex-lines too closely.

Boustrephedon, no less!

Can't be sure about some of the spellings due to the font being used, but the Atlas maps have "Mt Sheizer", "Duneizen Citadel", "Cult of the Maenads", "Rechtatzen Tor". Also, I couldn't read the second word after "Sturmhund", but it looks too short to be "Citadel".

I appreciate the variant spellings may be more poetic licence as a player's map, not a GM's, but the nature of this map and the multiple original Atlas maps makes following it for a GM difficult enough now, without such variants. If you'd prefer to keep the spellings you have now, I'd recommend also preparing a separate, complete, though more schematic, map for GMs only, so they won't have to struggle so much to keep on top of things and run the game.