You're right that Artificer is off the table, as I don't have the book with the original class in it.
As for the rest, that's quite a lot of info, so I'll try and sum it up to avoid a ton of copy and pasting.
Owning a BusinessIt starts with options for where you are opening the business--a city, a village, or even a traveling cart. It breaks that down further, like the difference in running a shop in the poor part of a city versus the wealthy part. It gives options for costs and rent for owning a storefront, how many customers it gets a day, and so forth. It also covers upkeep (cleaning and maintenance), supplies, staff (employees who work for you), signage, and joining a guild. I can elaborate further on any of these if you need me to.
The book offers a couple of examples I'll share here:
Chivalrous Knight FighterThose that wish to emulate the archetypal chivalrous knight strive to embody the qualities expected of an ideal knight: courage, honor, and a readiness to help the weak. These fighters live to serve and defend those that they hold dear, and they often seek love as well as glory.
Attention GetterStarting at 3rd level, you can distract your enemies to better defend your allies in battle. As a bonus action, when you hit a creature with a weapon attack, you can make a Charisma (Persuasion or Intimidation) check contested by the creature’s Wisdom (Insight) check. The creature must be able to hear you. If you succeed on the check, the target has disadvantage on attack rolls against targets other than you. This effect lasts for one minute, until one of your companions attacks the target or targets it with a spell, or until you and the target are more than 30 feet apart. You can use this feature three times. You regain all expended uses upon finishing a long rest.
People PersonAt 7th level, your training allows you to better read people. Whenever you make a Wisdom (Insight) check, you add a bonus equal to your Charisma modifier. Your skills also grant you proficiency in Charisma saving throws. If you already have this proficiency, you instead gain proficiency in either Wisdom or Intelligence saving throws.
Center of AttentionStarting at 10th level, you regain one use of Attention Getter when you roll initiative and have no uses remaining.
First Line of DefenseAt 15th level, you become a master of locking down enemies. Whenever a creature moves 5 feet or more while within your reach, they provoke an opportunity attack from you. If the opportunity attack hits, they take an additional 1d6 psychic damage and their speed is reduced to 0 until the start of their next turn.
Vigilant DefenderAt 18th level, you respond to danger with extraordinary vigilance. In combat, you gain a special reaction that you can take on every creature's turn except your own. You can use this reaction only to make an opportunity attack, and you can’t use it on the same turn that you take your normal reaction.
School of Concurrence WizardYou have chosen to focus your studies on symbiotic magic—spells that amplify the strengths of both you and others. While at first you learn to channel your magic into the power and protection of others, the connection grows stronger over time. Some concurrers are master tacticians, forging arcane connections that will devastate the battlefield. Others feel the deep bridge forged between souls and use the tethers to strengthen and protect those they love.
Synchronous SavantYour understanding of the soul has made you familiar with other types of magic. When you gain this feature, choose one of the following cantrips: Guidance, Spare the Dying, or Resistance. You learn that cantrip if you don’t already know it, and it doesn’t count against the number of wizard cantrips you know.
Concurrent TetherBeginning at 2nd level, you can tether your arcane soul to another creature as a bonus action, creating a magic bond between you that lasts for 1 minute. Choose one ally that you can see within 60 feet of you and one type of damage: acid, cold, fire, force, lightning, necrotic, poison, psychic, radiant, or thunder. The chosen ally’s attacks deal an additional 1d4 of that damage type for the duration of the tether. Your attacks deal the additional damage as well, provided you are within 30 feet of the target.
Once you use this feature, you can’t use it again until you finish a long rest.
The additional damage increases to 1d6 at 6th level, 1d8 at 10th level, 1d10 at 12th level, and 1d12 at 14th level.
Force ShieldBeginning at 6th level, when a creature you can see within 30 feet of you makes an attack roll against the target of your Concurrent Tether, you can use your reaction to rebound the attack. The attacker must make a Dexterity saving throw against your wizard save spell DC. On a failed save, the target takes half damage, and the other half is redirected to the attacker. On a successful save, the target takes half damage.
You must choose to use this feature before knowing whether the attack hits or misses. Once you use this feature, you can’t use it again until you finish a long rest.
Improved Concurrent TetherStarting at 10th level, you gain the ability to use your Concurrent Tether after finishing a short or long rest.
Arcane ConvergenceStarting at 14th level, your tether is at its strongest, benefiting both you and the target. When you cast Concurrent Tether on a melee or ranged fighter, you can use your bonus action to make a ranged weapon attack on your turn. When your Concurrent Tether is cast on a spellcaster, you regain a spell slot equal to 1/2 the level of the spell that was cast on them (rounded up) whenever they make a successful spell saving throw against a spell or its effects.