No, they are different calibers. A Glock 17 is 9mm and a Glock 23 is .40 S&W. A Glock 22 magazine would fit in a Glock 23.

Glock 23, IMO.

No. Because a Glock 26 is chambered in 9mm, as a Glock 23 is chambered in .40 s&w. For example you can use a Glock 22 (full size) in Glock 23 (compact) and in Glock 27 (sub-compact) But you cannot use Glock 27 mags in Glock 23 or Glock 22.

Yes, a Glock 19 9mm magazine can be used on a Glock 23 since both firearms are chambered in 9mm.

Yes