Wait a minute here FCPX does keep its in and outs similare to FCP7.
FCP7
Create your In and Out in your master clip add it to the timeline adjust your ins and outs on the same clip and ad that portion into the timeline.
Double click the clip in the timeline it will open up in the viewer with the ins and outs the same with the second clip from the same master clip.
FCPX
Mark your In and Out throw that guy in your timeline adjust the Ins and Outs from the same clip add it in your timeline.
Select the clip on your timeline and hit shift F you will get your In and Outs in the Event library.
Not sure what the issue is?