Company Jumpseats for personal use are fist come/first serve. The booking period opens about two weeks prior. Union employees (pilots/Mx/Dx) on personal travel all have the same priority and Booking window opens the same time. Non union employees booking window opens a couple days after the union employees. They do move a lot of crews on company business so that can bump you. Usually on a big deal on intl flights.
UPS dxrs are included in CASS.
If you wanna take family members, we do have discount ZED fares on a few carriers, DL and WN being the two majors. Couple others intl are good options.