Just wondered if these all need to be completed in Chapter 1,
Also before you meet the kingslayer after the meeting with Iorveth, are you able to do side quests afterwards?

No you won't. Remember to buy the unique recipies too b4 you go there.

which ones? The thing is I need to destroy the nekker caves still, but I need a recipe from Cedric first. I cannot locate him in his usual spot though. Also I need to do the meletele heart quest, but I need a troll tongue. I never killed the troll on the quest so not sure what to do.

Kayran armor and armor upgrade are the one I meant. Cedric is hanging out in the village. Watching the forest during the day or hanging out by the fire where the other folks meet during night. His house in by the fire as well.

I cannot help you with meletele quest, because of my choices I didn't get the medalion.

neither did I. I didn't get the medallion but I used a mod. I found Cedric but oddly he wasn't at the lookout point during the day.

Cedric has a crafting icon that shows him on the minimap. He can be wandering around, but since he has an icon, you shouldn't have an issue finding him.

Troll's tongue can be gained by a troll's head, which is won by beating the owner in dice, or killing a troll. I believe you even keep the tongue if you decide to give the troll's head to the troll, as the tongue is a separate item that enters your inventory when you gain the head (I could be wrong, as I never bothered to give the troll the head).