We've got several XD's, XDM's, and the SC version which my Daughter in law carries. She is a small woman and hasn't had any experience what so ever prior to my Son buying her the XD SC, and she quickly took control of the functional operations. And quite honestly, the slide is so smooth and anyway. If I had to complain about anything regarding the XD it would be the 17 round magazines being almost impossible to load to capacity, without the use of the speed loader that comes with them. If the holster is well matched to the person, and their carry style, to which there are many holster options available, it should be very comfortable to wear.
But even if it's a no go regarding the slide and carry problems, melting it, and, or clipping or replacing springs that may, or may not be specifically intended for the XD, would be a shame, not to mention destructive in my option. And as already established by another individual here, the XD's are as close to perfectly reliable as it gets.
When someone buys a handgun, it is imparative they take the time make sure it fits their physical abilities in every aspect. By melting and making other bizzar alterations is just asking for trouble. And it's an XD, selling it, or trading it in for near what you've got into it shouldn't be to difficult to accomplish.