When i add a stem track, is it possible that the 1-4 cue buttons auto switch to the stem mute buttons?
Out of the box, no.
You can modify the code to do all kinds of things, but it's not invitingly easy to do. Check out the community mod featured right here in this forum to help you out with controlling stem parameters with one or two button switches. It's much easier to install and use than it is to start coding and was conceived to eliminate a few of the X1 shortcomings.