1a - Stick in the Mud - Perhaps make Voran's buried teleportation circle more visible once the mud is cleared out. It isn't of immediate use but it makes a nice detail for later on.
1b - Den of the Slavetakers - Instead of Torog, use Chitteruk. "Hand of Torog" rolls off the tongue better, but Torog has little else to do with the Scar and using Chitteruk more than once adds some consistency.
1f - Some Assembly Required - Dardun is relocated near the King’s Wall and the mine that the kobolds are hiding in are located within the Scar.
1i - Elves of the Valley - When the Voice in the Darkness is destroyed, have a Chaos Shard be embedded near the base.
Torak Banehammer - Torak can be a good source to run a series of quests as he searches for the Hammer of Ivak. He might suspect the duregar Barulg from The Hammer Falls of having the hammer first and then perhaps suspect the lost temple of Erathis from Dead by Dawn is actually the lost temple of Moradin before honing on his final destination. He can make for a useful companion character, too.
2h - Slaark's Crown - Nothing needs to be done with adventure but the rivalry with Urgog's goblins in Down the Goblin Hole can be played up, perhaps with Slaark trying to hire the party to take out Urgog.
3c - The Wayward Wyrmling - Have the Stormcrows kill Karonzaxus for a bit of continuity.
3d - Storm Tower - The tower is along the King’s Wall and Lord Drysdale intends to use it as a watchtower which was its use back when the heroes lived there.
3e - Fjorin's Foothold - Can pretty much be played as-is except for its location in the Scar. If you'd like, consider re-skinning the chitine into creepier star-touched baddies whom Fjorin has made a devil's bargain with.
4c - Vanguard Tower – The adventuring group that used to own the tower is almost completely irrelevant. Instead have the tower be Voran’s, mysteriously in tact after the star fell, complete with another teleport location for the PCs to use. The teleportation circle is activated by pouring a decanter of seemingly endless oil on it - the decanter is in the tower.
4d - Stormcrow Tor - The Wrathstone is made from a potent chaos shard and was obtained from the Banite's keep.
4e - Blood of Gruumsh - This doesn't really need any changes; the Scar seems like a perfectly good place for the Colony to try and hide.
6b - The Radiant Morn - Consider having the cultists follow Chitteruk or some other non-existent deity instead of Baalzebul.
7e - Vainglorious - Replace Torm with Moradin. If you'd like, have Torak Banehammer give the quest. If you'd like to keep Moradin followers dwarfy then change Sir Tavil Soarvaren to Tavil Banehammer, Torak's older brother.
8c - The Star touched Grove - The grove is now a remote wilderness location. Use the setups in the rumor and job lists to establish things.