I will point out that quiet parameter means non-verbose - which is why you will see lines of code.
The splash parameter sets Plymouth. splash screen. Neither of these will halt boot if enabled.
So please keep an eye on this.
Try one thing, take a tweezer or something similar. then place it in little gap between the key and the board. Gently pull it a little up (don't use too much force) and hold for 5sec then release. Do the same for both non-working keys.
This sometimes helps fixing the Sticking key but the result is not guaranteed.
You could try a few drops of Isopropyl Alcohol (cleaning fluid) around and under the stuck keys and tap them to see if that helps. Then hold keyboard upside down and shake out any surplus fluid.