I have to make the window bigger to see all the long names

You can make the window bigger, or the font smaller, or the panel or its columns wider, or scroll the long names manually, there are quite a few options.

And it does not seem too advanced with color theme management

In theory we could introduce a proper UI for this, with a list of available themes, preview, export etc.
I even have a draft branch somewhere.
However, usually you only try other themes once, realize that you don't like them anyway, come up with your own and stick to it till the end of time, so there's not much motivation to make this too advanced.

So I have to make the window bigger to see all the long names.

In order to use it comfortably, the shortcut to the programme needs a little tweaking. But my system does not allow me to change the shortcut in the start menu. So I choose a location (right mouse button, properties), open C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Far Manager 3 (x64) - with the Shift key pressed I drag the shortcut to the desktop, change it there (with confirmation from the administrator) and bring it back. Then I link it to the start menu and the desktop.
What I change in the settings of the shortcut for comfortable use: 1. shortcut/window - I change from ‘expanded to full screen’ to ‘normal window size’; 2. shortcut/additional: ‘run as administrator’; 3. font = 14 ‘Consolas’; 4. location/size of the window 200/60. You get a very convenient interface that does not overlap other windows. Besides, it can always be ‘pushed’ aside. I also put ‘quick call’ = Ctrl+Alt+F. And at any second I can call FAR by pressing this combination.

I am going to do that, thanks.
There might be a somewhat difficult accommodation to Far for new users, mainly because it is text mode.
So no comfortable interaction with the rest of the GUI software, like drag-and-drop.
Also the window space is not as efficiently used when all the fonts are fixed width.
But the interface is clear, very well organized, with a lot of advanced options. It shows it's maturity.
With a nice theme, there is a certain sweetness to Far.

... because it is text mode.

Well, it's the whole point of using Far. In exchange, you're getting a real, honest command prompt and console. You can run (virtually) any command line application, and it will work exactly as you would expect it. I believe there is no way to emulate console in a GUI application with this level of fidelity (unless you use another console emulator). For example, if you use a command line script to set up a complex command-line-based development environment (which is often the case), you can launch Far at the end of such script and have the fully functional environment plus Far panels and all other goodies.

... like drag-and-drop.

While you cannot drop a file from Explorer to Far (but why do you use Explorer to start with? 🙂) you can copy file's full path with Alt+Shift+Ins and paste it directly to any GUI "Open" or "Save" dialog. This trick replaces dragging file from Far to GUI applications and works like charm.

You are right about Explorer :)
But unfortunately the Desktop is still Explorer.
I found this plugin (https://github.com/VictorVG/PLG/blob/master/Drag-n-Drop.7z), which should add support for drag-and-drop to Far.
The problem is that when I try to drag a file from Far to Desktop it badly freezes my ConEmu+Far. But if I am patient through the freeze, the control is returned and the file is copied.

If you are using ConEmu, it already provides support for drag and drop with Far. Look at Settings -> Far Manager.

Have you installed the ConEmu plugin in Far?

@bitraid
Hey, it worked!
I copied ConEmu directory from \ConEmu\plugins into \Far\Plugins. And restarted Far.
Now in F11 menu I have 4 new ConEmu entries.