The 3D remake's "Eureka_Battle" file contains all of the text relating to battle, whether that be the menu text or the actual in-game text. This includes the names of the various commands. However, looking at the list, there are a significant number of commands that go unused in the final game.
The interview at the back of the FF3 DS Japanese strategy guide mentions that a multiplayer vs mode was conceptualized for the game, with numerous commands created just for it. That would imply that these commands are actually a remnant of this mode. It is possible, however, that some of these commands were intended for the main game or were remnants of previous job concepts.
While the commands are listed in the file, there are no descriptions nor any significant indication of which commands belong to which jobs. Thus, the descriptions and job associations I provide are based on their appearances in other Final Fantasy games and are simply my speculation.
This one is likely clear. It was more than likely a means of switching rows. In the final game, "Front" and "Rear" are their own commands.
Chakra is usually a command that restores HP to a character (and sometimes cures status ailments or recovers MP). It is a recurring ability of the Monk so it likely would have gone to that class or to the Black Belt.
The Chainspell command was introduced in Final Fantasy V and has since been a staple of the Red Mage. The ability was introduced as a means of buffing Red Mages while keeping them restricted to the lower spell slots: It gives the Red Mage the ability to cast multiple spells at once.
Hide is yet another recurring ability. This ability allows the character to flee offscreen - preventing them from being targeted as well as doing much of anything. Hide was introduced in Final Fantasy IV as an ability of the infamous Bard Edward and is usually associated with Bards as well. However, Final Fantasy XI (from which the III remake takes significant influence) gives the ability to the Thief while The 4 Heroes of Light, which Team Asano would work on next, gives it to the White Mage
This one is interested: Berserk is a recurring status in the Final Fantasy series that increases affected character's attack, but makes them only do their basic attack - as well as become uncontrollable if they are a playable character. However, in Final Fantasy XI, Berserk has a different effect. Namely, it increases the user's Attack, but lowers their defense. So technically, Berserk is in the game - It's the Warrior's unique ability, Advance.
This one is tough: Bash appears in numerous games, but strictly as an enemy exclusive skill. Since this is grouped with the job skills, it's unclear exactly what it is for, other than that it was either a Warrior or Knight skill.
Cover is also an ability that's technically used: But it's passive ability that automatically activates rather than a command.
Sentinel is an ability introduced in Final Fantasy XI and recurs in several games afterwards. It usually increases the user's defense and sometimes causes them to grab the attention of enemies. This was almost certainly a Knight skill, though it may have been axed due to overlap with Viking's Provoke.
Aim is a recurring skill, introduced in Final Fantasy IV as Rosa's personal skill. It's a skill associated with increasing accuracy of attacks - as such, it's sually given to an archery or gunner job, including the Ranger job.
Shadowbind was introduced in Final Fantasy IV as part of Edge's Ninjitsu. It paralyzes the target if successful. It tends to go back and forth between being a Ninja or a Ranger ability, but Final Fantasy XI gae it to Ranger and it's grouped with Barrage and Aim in the data for this game.
Another interesting case: Gauge is actually the original Scan prior to those abilities being merged into one for the remake. It's unclear if Gauge would have been overhauled in some fashion before being dropped for Item Lore, if it's just there as a leftover or if would be a multiplayer exclusive ability.
Much like cover, Alchemy technically exists in the final game, under the name Item Lore and as a passive. The interesting part is that the Pixel Remaster would later revist this idea: Alchemy is a command in that version and functions as Item Lore does in the 3D remake.
Control is a weird one. It's Japanese name is "つかい". To my knowledge, that word has not been used as a command before and translations of it tend to be "Errand (boy/girl)", Familiar (in the sense of a spirit like Unei's Parrot) or a Trainer/Tamer/Charmer/etc.
The command itself is between the Scholar and Dragoon Commands, but it is unclear if it means the Scholar was intended to Beastmaster leanings or if Dragoons would be able to summon wyverns alongside them (as they do in Final Fantasy XI).
Abduct is a unique command, in that we know what it does and why it was made: It was made for the multiplayer, it was a Dragoon command and the character would have grabbed the opponent before leaping into the air and slamming them into the ground (i.e., a flying suplex).
Blood Weapons have appeared in the series since Final Fantasy II's infamous Blood Sword, which III followed up on by introducing a Blood Lance. However, the Blood Weapon command, which grants a weapon that status, has been linked to Dark Knights since at least Final Fantasy Tactics, where Gafgarrion's abilities allow him to heal off of damage he inflicts. Similarly, Final Fantasy XI also gave Dark Knights the ability.
One of the stranger abilities. It's a new ability to the 3D remake and the best connection I could find is to FFXI's Cardinal Chant ability for the Geomancer. Other than that, it is near impossible to tell how this move would have worked.
Another apparant Geomancer job with no clear connection. Geomancers in FFXI are associated with Feng Shui concepts and the concept of ley lines/dragon veins/a natural power flowing through the world relates to that. Aside from that, though, it's pracically impossible to tell what this ability did.
Charm is peculiar. The Japanese name, "あやつる" refers to the line of spells that allow Beastmasters to control monsters. But the command exists between the Black Belt and Ninja jobs. Take that as you will.
A weird case, as dual-wielding is not only in Final Fantasy III, it's downright encouraged. As this is located with the Ninja commands, perhaps Ninja was going to be the only job to dual-wield in multiplayer?