2. Delayed key-tone-reaction (especially with Windows)
This is a reason to prefer an Apple-Computer. But also Windows with a latency of about 50 milliseconds allows to practice fast pieces.
You just might have to deal with the strange experience that sometimes a tone starts sounding after you already have pressed the next one!
The Physician Stefan Klein describes a similar effect in his book "Zeit - Der Stoff, aus dem das Leben ist", in chapter "Flugzeuge, die Gedanken lesen" on page 98-99.
But anyway: Beginners better start practicing slowly.
3. Limited Polyphony (simultaneous pressing of different keys, e.g. chords)
Up to now your pc keyboard is designed for just writing, not playing music.
And it doesn't make sense to write more than one letter to the same place.
For that reason poliphonial playing is limited . So better try to play the tones fastly one after the other instead of playing them altogether (->Arpeggio).
Just simple technical approvements are needed to make the pc keyboard a fully competitive musical instrument creating much fun, even when played on a stage. Although these approvement on the keyboard have not been made yet, it is already valuable to give it a serious try!
And here's an advantage: The pc keyboard allows to dance while playing!