What does Fine Gold Thread reward?

Fine Gold Thread gives Fine Gold Thread outright.

Where does Fine Gold Thread start?

It was picked up in Stranglethorn Vale.

Its level has not been recorded yet; it shows once a player accepts it with the addon running.

Yes. Its quest id is not in Classic Era, so it is part of what Forever adds.

World of Warcraft: Forever · quest · new since Classic Era

A quest in World of Warcraft: Forever in Stranglethorn Vale and turned in to Xizk Goodstitch. Recorded by 1 player running the addon.

Level, giver, pay and objectives show once a player with the addon accepts the quest.

Item	Given	Item level	Vendor sell
Fine Gold Thread	outright	1

What does Fine Gold Thread reward?: Fine Gold Thread gives Fine Gold Thread outright.
Where does Fine Gold Thread start?: It was picked up in Stranglethorn Vale.
What level is Fine Gold Thread?: Its level has not been recorded yet; it shows once a player accepts it with the addon running.
Is Fine Gold Thread new in WoW Forever?: Yes. Its quest id is not in Classic Era, so it is part of what Forever adds.

Source: what players running the addon saw in the quest windows; the quest text itself stays in the game. Every quest seen · Stranglethorn Vale