The force lance is going to give you some problems if you use Traveller type tech. The extension staff and shock capabilities are simple enough, but being able to fire a huge supply of effector drones, or plasma bursts is a bit dicey. Granted that the effectors are supposed to be microscopic... but I just can't see them being able to pack enough whallop for macroscopic objects without some serious change in the tech.
So, If you're modeling them in Traveller terms, I would consider the weapon to be a hardened laser carbine or rifle, with stun/shock wand capability. (OK, a REALLY hardened laser, considering that you're going to be bashing people with it.) Stats would be as follows:
Force Lance MK I: TL-15 hardened laser/melee weapon. Cost: Cr10,000. Availability: Cat-5.
Compact mode:
baton, 2.5kg, 1d6 damage (bludgeoning). 45cm in length, 3cm in diameter.
Shock baton, uses one "shot" to deliver an electric stun charge (Fort save, DC20 or incapacitated for 3d6 turns, save takes 1d6 extra stamina damage only.) In any case, only the tip caps are charged and the user must take care not to shock him/herself when in use.
laser carbine: 3d8 damage, range 45m
Staff mode: 3cm diameter at middle, 1.5cm diameter at distal ends, with tips flaring back out to 3cm for the last 5cm.
weighted quarterstaff:
2.0m in length, mass unchanged. 1d6 damage, but with reach and considered to be a double weapon.
shock mode, as per above.
laser mode increased in range, but with no change in damage. Range is now 60m due to increased focal length.
Capacitor charge holds 20 shots. One shot will power the laser once, or one electric shock to the baton. Recharge and re-arming is per standard laser carbine, except for the lack of an external power supply. Force lances have a side mounted port which will accept power feed from the standard laser power packs. Users will often carry beltpacks for field recharges when on maneuvers.
The force lance can be set to register its user's bio-metrics and will deliver one charge per turn to an unregistered user until the capacitor is discharged or the user puts down the weapon.
Force Lance Mk II:
Same as Mk I, except can uprate the damage upon command to perform as a laser rifle. Uses an extra charge for laser mode.