Hi @Vitos,
Currently, Hookpad does not allow you to input chords through MIDI by playing the chord tones simultaneously (however, this is something that we’re looking into for the next version of Hookpad). I apologize that you were given this impression, and we would be happy to issue you a refund.
Regarding the “stupid stuff”: Hookpad, and Hooktheory more generally, is based entirely on the idea that you should learn the music theory. If you are happy just playing chords without thinking about music theory, then Hookpad probably isn’t the right tool for you. If on the other hand, you are interested in understanding why certain chords sound good together, or how to write new and interesting chord progressions, then Hookpad’s music theory will be a powerful companion. It can teach you things like: in the key of G, like in “If I Ain’t Got You”, you don’t typically use chords like C7, B7, or G7 (a good indication that your chord chart is not correct). Much more common would be: Cmaj7 or C, Bm7 or Bm, and G or Gmaj7.
Music theory may seem difficult to learn, but the basic concepts are actually quite simple and extraordinarily useful. Hooktheory offers two books on music theory here:
https://www.hooktheory.com/music-theory-for-songwriting
Regarding entering chords in Hookpad: The opening piano riff actually goes: Cmaj7 → Bm7 → Am7 → Gmaj7. In Hookpad you would write these chords as: IV7, iii7, ii7, I7 in the key of G. In fact, the Hooktheory community has already written out the chords to this song here:
https://www.hooktheory.com/theorytab/view/alicia-keys/if-i-aint-got-you
Hope this helps!