I see one missing: RAAN, the right ascension of the ascending node. Sometimes longitude is used instead, but right ascension makes it clear that you're measuring it in an inertial frame, not a rotating earth frame.
Another parameter often used is C3, twice the specific orbital energy. It's used more often in escape trajectories but is valid for any orbit. It's twice the sum of the potential energy per unit mass plus the kinetic energy per unit mass, a constant for any 2-body orbit not experiencing drag or thrust. It's defined as zero for an exactly parabolic escape trajectory, so it's negative for a closed orbit and positive for a hyperbolic escape trajectory. This convention makes the math far easier in the N-body problem.
Can it display Cartesian coordinates, aka state vectors? That might be somewhat more intuitive, or at least show the same data in a complementary way.
While metric/SI is the way to go for spacecraft engineering, another set of units you should probably know about are "canonical" units. They are normalized for a given planet so that its gravitational parameter is 1. The canonical unit of distance is a (usually equatorial) planetary radius, canonical velocity is the velocity of a surface-skimming satellite, and a canonical time period is the time it takes to go 1 radian around on a surface-skimming orbit (i.e., one canonical distance unit along the orbital track). Many tracking programs use these units internally to minimize roundoff problems and then convert to SI on output.
