InSight

There is lots of work to be done.Do we know everything about Mars.the answer is no.Mars is far from a dead world. The volcano on Mars might still be active just because we don't see them active,don't mean they aren't. The only way to be sure is to land a space probe InSight

Its was design to measure heat coming from the surface and if there are any Mars quakes
The Seismic Experiment for Interior Structure (SEIS) will take precise measurements of quakes and other internal activity on Mars to better understand the planet's history and structure. SEIS is provided by the French Space Agency (CNES), with the participation of the Institut de Physique du Globe de Paris (IPGP), the Swiss Federal Institute of Technology (ETH), the Max Planck Institute for Solar System Research (MPS), Imperial College, Institut Supérieur de l'Aéronautique et de l'Espace (ISAE) and JPL. The seismometer is a sensitive broad-band instrument designed to detect sources including atmospheric excitation and tidal forces from Phobos.
The Heat Flow and Physical Properties Package (HP3) instrument, provided by the German Space Agency (DLR), is a self-penetrating heat flow probe —nicknamed "the mole". Also called a "self-hammering nail", it is being designed to burrow up to 5 m (16 ft) below the surface to measure how much heat is coming from Mars' core, and thus help reveal the planet's thermal history. It trails a tether containing precise temperature sensors every 30 cm to measure the temperature profile of the subsurface.
Rotation and Interior Structure Experiment (RISE) uses the spacecraft's radio to provide precise measurements of planetary rotation to better understand the inside of Mars. X-band radio tracking, capable of an accuracy under 2 cm, will build on previous Viking and Pathfinder data. The previous data sets allowed the core size to be constrained, but with a third data set from InSight, the nutation amplitude can be determined. Once spin axis direction, precession, and nutation amplitudes are better understood, it should be possible to calculate the size and density of the Martian core and mantle. This would increase the understanding on the formation of terrestrial planets (e.g. earth) and rocky exoplanets.
A camera mounted on the lander's arm can capture black and white images of the instruments on the lander's deck and a 3-D view of the ground where the seismometer and heat flow probe will be placed. It will then be used to help engineers and scientists guide the deployment of the instruments to the ground. With a 45-degree field of view, the camera will also provide a panoramic view of the terrain surrounding the landing site. A second similar camera, with a wide-angle 120-degree field of view lens will be mounted under the edge of the lander's deck and will provide a complementary view of the instrument deployment area.
Some payload augmentations by the summer of 2013 included a high-resolution (finer than 10 mPa) pressure sensor, REMS wind sensors, a ground temperature radiometer, and a magnetometer. The seismometer (SEIS) needs to detect ground movement at a resolution of about half the radius of a hydrogen atom. While this level of sensitivity has been tested, it means carefully mitigating noise from the planet and lander.
A color camera was also considered, but there is a lack of funding for this item.
Solar cells was used to reduce the amount of money that is spend. Since it only to live on the surface for 1 Mars year. Unlike the Mars Rover which used RTGs as power source but these RGT weight a lot plus their cost lots.Plus they used the plans of the old Mars Phoenix lander,The plan landing site is Elysium Planitia .They are looking for the lowest point on the surface of Mars but it also has to be a safe landing site as well NO trip into Valles Marineris which would be the place to go,in some areas it 5 mile deep. This canyon makes the Grand Canyon on Earth look small
But to answer your ? Yes if Mars had a more active core it could had created higher mountain ranges, since now they think that Mars have a two Plate tectonics in action. On Earth was have 7 or of them...... But because the inter core of Mars oh well have come to a almost stop. Maybe we are look at Earth in few billion years after all the radioactive power source stop and Earth core slow down and stop making a magnetic field and Earth would become another Mars...