Oliver, I'm not sure even YOU know what you're asking. I don't say that to be mean, but to emphasize what Band In A Box does.
When you create a song in BIAB, either using Real Tracks or MIDI, it takes the chords and then generates a five-part backing track.
So, each chord symbol you put in the window, if you're only using MIDI, will automatically generate a drum pattern, a bass pattern, a guitar pattern, a piano pattern, and a string pattern. Actual instruments may and will vary depending on the style you chose.
So, if I'm doing a simple 12 bar blues song, I may have C/C/C/C/F/F/C/C/G/F/C/C. Just putting the chords into Ableton doesn't accomplish anything as far as Band In A Box is concerned because BIAB is going to create a five-part accompaniment to go along with that chord progression. Pick any blues style from the Style Picker, especially one suited for blues, and that's what you're going to get. Take the same chord progression and pick a Klezmer style if you want, it doesn't matter.
Your comment of "I want then the series of chords in question RAW, NO music style, NO Real Tracks. NOTHING." and then "I want this simplicity of being able to type in the name of the chords (and then being able to listen to them)" are directly incompatible with each other.
So, what we need to know is this. If you type a chord progression, say the blues progression above, into BIAB, what do you want to hear? Do you want to hear drums, bass, piano, guitar and strings (or approriate instruments), or do you just want to hear nothing?
Every song, no matter what it is, has a 'style.' It could be as simplistic as a simple strummed guitar for each beat the chord falls on, with nothing else but that guitar, or it could be a fully orchestrated piece of music by John Williams (which is far beyond the scope of Band In A Box). No matter which you choose, it still has a STYLE.
Now, you can simply choose not to buy any Real Tracks, that's available, but I'll tell you, if you're making your own songs, especially for demo songs, RTs are invaluable. Unless you are a multi-instrumentalist and can play all your own parts, they really add a certain je ne sais quoi to a song. Even some of the most sophisticated VSTis can't compare to a real live player.
But, that is neither here nor there until we find out exactly what YOU want from BIAB, and right now, to me, I don't think you know what you're looking for, or you do, but you're not expressing it correctly.
Why don't you give us a run down on what you want to hear.
I want to go WAAAaaay back in time to Band In A Box 9, which is ages old. This version predates Real Drums and Real Tracks. The following video goes over available styles in that version.
https://www.youtube.com/watch?time_continue=47&v=zW-v9n-XrWM&feature=emb_logoHere's a video from Band In A Box 7, which again predates Real Drums or RealTracks.
https://www.youtube.com/watch?time_continue=16&v=XveLIVrqgRU&feature=emb_logoAll Band In A Box versions allow you to input your chord progression, but they MUST output something, and that something depends on the style that you choose.
If you don't want ANY style, then I suggest that writing the chords in Ableton, if you can, and going that way. If you can't do that, then maybe a different sequencer for you?