I'd like to be able to fletch arrows, though I got like 2k in my house. I put them on the dinner table when I have guests around. Everyone needs a toothpick once in a while.

There is a shop at the "Castle Dour", in "Solitude", just before you enter the castle... The guy there sells a lot of arrows. Seems to be a hunter. Many hunter camps (The bear-claws), have hunters that will sell you arrows.

I always find plenty on dead bodies in dungeons. Use your stealth-attack for the first shot with an arrow, that will save you like 10 or 20 unrecoverable arrows when you kill creatures.

Would be nice to craft them, but I have never run out... So I won't complain about that craft being missing in the game. (Would have been better than cooking.)

Because we alread have enough of them. And besides you don't forge Arrows, you fletch arrows.

If you are looking for some better arrows, pickpocket Karliah from the Thieve's Guild