I haven't published this app yet, but I uploaded an APK with a critical bug in it by accident, and I want to replace it. Can I still just remove and upload a new APK?
My main two concerns is that 1) I will have to change the version code and version number somehow because Google already signed my old apk and 2) I already completed all of the content rating, descriptions, ads or no ads, etc. settings. Do I have to do them again or will there be some sort of problem there?
Thanks!
Update 16 Feb 2020
As pointed out by @tuexss in the comments, the Artifact Library has been replaced by App Bundle Explorer
Original Answer
You can upload a new APK with the same version code and a version number if you haven't published the old APK. All you have to do is discard the current release, go to the artifact library and delete the old APK and then create a new release from the console and upload your new APK with the same version code and version number.
If you have published the old APK, i.e., you have pressed the start rollout to production button then you need to upload a new APK with increased version code. The version number isn't mandatory to be increased in every new release although increasing it will help you track the data in a better way.
In either case, you will not have to fill out the play console details again.