Subchapters named "important characters" list mostly merchants and other people that you can trade or interact with, but it's not related to any quests.
Hint 29: When you buy an item from a merchant, he'll have another unit in stock the next day (the only exceptions are valuable items such as meteorites, runes or books).
She sells: Saltpeter, Stammelford's Dust, Goose Fat, Suer, Temerian Rye, Local Pepper Vodka, Cherry Spirit Cordial, Plum Cordial, Calcium Equum, Wine Stone, Ginatz's Acid, White Vinegar, Naezan Salts, Zarrikanian Mix, Bear Fat, Lunar Shards, Powdered Pearl, Barghests, Wormwood Spirit, Sulfur, Phosphorus, Alchemists' Powder, Alchemical Paste, Specter Oil, The Book of Animals, Swamp Monsters, Red Ribbon.
You'll find him in the inn (M5.3). He offers the following books: Recent History, The history of the world, Barghests, Monstrum or a portrayal of the witchers, Fairytales and stories, The conjunction of the Spheres, Ithlinne's Prophecy, An Invitation to Magic, Basics of Alchemy, Against Nonhumans, The Book of Animals, Field Plants, Zerrikanian Alchemy, Swamp Monsters, The Tome of Fear and Loaghint vol 1.
You'll find him in the inn (M5.3). If you pay him 5 orens you'll find out about Dandelion.
Declan Leuvaarden (merchant)
You can't trade with him until in chapter 2.
Haren Brogg (merchant)
He's usually standing by his house (M5.49). You must have the Eternal Fire Ring put on for him to talk to you. You can get the ring from the Reverend (M5.22, M5.25) during Q1.6. Salamander's Tail, or from a beggar (M5.18). He sells: flint, whetstone, saltpeter, suet, goose fat, temerian rye, stammelford's dust, grindstone, bear fat, zerrikanian mix, axe, temerian iron dagger, temerian steel dagger, small axe, temerian iron axe, temerian iron sword i blue meteorite.
You won't be able to trade with him until chapter 2.
She conducts business near Vizima gates (M5.23). She'll tell you that Berengar probably went to Vizima. You can buy here: She sells: chicken leg, mutton leg, Loj, goose fat, pork, chicken i bear fat.
He can be found in his workshop during the day (M5.5) near the inn. Blacksmiths can forge steel swords from meteorite parts and place runes on silver swords. If you talk to him about weapons, he'll sell you a recipe for Crinfride Oil for 35 orens. Don't ask him about Squirrels, because it will anger him.
You can find here near one of the gates (M5.26). She'll give you tulips in exchange for some field flowers.
He can be found in the inn (M5.3). If you can drink more than him (5 pints of beer or three bottles of wine should do the thing), he'll give you a book on Ghouls and Graveirs.
He wanders around the road with the most chapels by it (M5.8). He'll give you 100 orens if you talk to him.
They're near the chapel (M5.22). In exchange for food they'll tell you a story about Drowners. You'll gain knowledge of new alchemical elements: Ginatz's Acid, Drowner Brain Tissue, Cadaverine. For some more food they'll teach you about Ectoplasm, Werewolf Fur, Abomynation Lymph.
They wander around the houses (M5.16, M5.18, M5.20). You must give them food if you want to talk to them (for example bread). Ask them for a story to know about Ghouls. Ask about herbs to know about Balisse.
Vesna Hood (merchant)
He works at the inn (M5.3). You can buy: Bread, Kaedwenian stout, Visimian champion, Grapes, Pears, Goat's Milk, Cow milk, Mettina rose, Mahakaman mead, Toussaint red, Watermelon, Chicken leg, Cheese, Mutton leg, Redenian herbal, Goose fat, Temerian rye, Dried fruits and nuts, Cherry spirit cordial, Temerian spirit.
He usually sits by the fireplace (M5.9). If you talk to him, you'll know that some monster is troubling the people by the river, near Haren's house (M5.49) and that inside the crypt (M5.39) there's something wrong going on.
She is walking around the houses (M5.16). If you want to make love to her, give her Tulips that you found by the dead body (M5.13), and then say "Let's find someplace...".
The Herbalist (merchant)
He's usually near the inn (M5.2). He sells: Raspberries, Blueberries, Apple Juice, Raspberry Juice, White Myrtle Petals, Hellebore Petals, Sewant Mushroom, Daisies, Balisse Fruit, Honeycomb, Orchids, Field Plants.
You'll meet her near the houses (M5.18). Give her White Gull, and in exchange you'll get Eternal Fire Ring. It might come in handy, if you want to talk to Odo, Mikul or Haren.