Morrowind Role-Play: The Merchant
Danae's excellent Ahead of the Classes adds more than 100 new playable classes into the game. Here's a roleplay guide for one of them: the merchant. The assumption for this roleplay guide is that one would roleplay the class in a very strict fashion: it's a character whose goal is to acquire money by trading items and finding unique and valuable items for making good deals. You are not a Hortator/Nerevarine/Leader of multiple factions in this playthrough just a person who wants to get rich. Possible end goals could be buying a house, for example, through the IndyBank mod recommended down below, or acquiring 1 million Septims. Perhaps you want to use the "Mesa Exchange" feature in Tamriel Rebuilt's Grasping Fortune release to invest the gold you've earned into stocks and live off from passive income. As far as handicaps are concerned you shouldn't use the Creeper of the Mudcrab Merchant at all because it ruins the fun. When traveling, you should stick to the roads - you are a merchant whose goal is to travel from settlement to settlement looking for good deals, not somebody seeking adventure. Also don't do anything at else during night, except for sleeping: businesses are closed at night! (Even if not by vanilla mechanics.)
For a merchant playthrough, I recommend playing an Imperial who was born under the sign of the Lady as both of these give a huge boost in personality which is necessary for trading.
While it would seem logical to join one of the factions that are suitable for merchants (House Hlaalu or the East Empire Company), I do not recommend this for two reasons: firstly, some of the quests of these factions involves things that you might not want to do, such as killing. And secondly, members belonging to faction that are hostile to these factions would hate the player: and that results in worse prices. In fact, I generally recommend turning down quests most of the times: you are a merchant, not a problem solver or a hero(ine)!
However, there are a couple of exceptions:
Some quests offered by merchants, such as “The Shirt of His Back” and “Weapon Delivery”: your character might want to develop a better relationship with merchants. The Tribunal quest, "Champion of Clutter" is also a fun way for roleplaying a merchant: just pretend that the quest-giver is a customer who orders specific items from your merchant character's company.
As far as gear is concerned, exquisite clothes and Telvanni Bug Musk are a must, as part of selling something is first selling yourself. (And they come with a Personality boost.) Have a common robe too, for traveling through ash storms: you don't want your precious skin and clothes ruined. Since you own your own business and your success is your responsibility alone, you can’t really have a sick day, so consider investing into a Cure Common Disease and a Cure Blight Disease spell.
Mods:
As for any non-Nerevarine character, CREL is necessary: you won't be forced into the Main Quest this way. And it makes the CharGen part of the game significantly shorter too.
Necessities of Morrowind or Devilish Needs (Vanilla/OpenMW) or Ashfall (MWSE): It makes it necessary for the player to eat, drink, and sleep regularly. Just another way to get immersed in a character who is not a hero with superhuman abilities.
Import Business; The Merchant of Vvardenfell: Probably the most essential mod for this. You can order wares at the East Empire Company office using a ledger, and the wares would appear in a crate at the warehouse after some days. You can order alcohol, weapons, armor, books, clothing, or miscellaneous items. Then you can go around in Vvardenfell, and sell these items.
Guars (Vanilla/OpenMW) or The Guar Whisperer (MWSE): Why not have a guar to carry all your merchandise around?
Staff Agency or Mercenaries Beta: Hire mercenaries to protect you and your merchandise on the road too.
Service Refusal Expanded: Makes rolepaying a merchant even more immersive. In Telvanni territory, you would need to possess the “Hospitality Papers” to do business, and you would need an “Imperial Charter” to deal with ore or Dwemer items. Also, no one will be interested in buying any gross item that you may collect, such as human flesh.
Consignment Chests Expanded: Adds consignment chests to particular in-game traders. Items can be placed in the consignment chests, at which point the particular trader will begin to save the required gold to buy the item. For each full day that the player does not visit the trader, the trader will save their daily supply of gold. Once the trader is able to afford the item in the chest, the item will be removed and replaced with the gold. The price offered is based on the player's Mercantile skill, and is generally a bit lower than if you bartered directly.
IndyBank and/or Project Tamriel's (TR, PC, SHoTN) Briricca Private Bank feature: Take out a loan to kickstart your business, or deposit the money you've earned. With the roads being so dangerous you can't just carry all that gold around.
Sails and Sales: If being a merchant on land is not enough for you, with this mod you can become the captain of your own ship, recruit crew members and acquire cargo to sell. (Requires MWSE)
Divine Providence (Vanilla/OpenMW) or PRAY (MWSE): You can pick Zenithar, the god of commerce, as your patron god and gain perks and abilities from him.