These are fixes that would make Restless Isles much more player friendly - I'll leave the Raids themselves to others who've run those Raids more than I to suggest fixes for.
1) Missing Beholder in Slavers of the Shrieking Mines {Optional Uncompletable}.
2) DCs of Gates/Doors and Chest in Slayer too high {Currently 47-50, Drop to 42-45}.
3) Wildman Rare should be always there - You have to get the Golden Figurine from Slavers before you can even get to him in the first place so make him 100% Spawn.
4) Raid Groups have to use Greater Teleport to get to the Raid because the entrance to the Raid is in a Public Instance only reachable through the Non-Raid Slayer {Give the Slayer a Raid Setting.}.
5) The Map - Like all Inside/outside quests {and quests on multiple levels} the map simply doesn't work.
Surely it's time to work out how to make usable quest maps for these instances {The Pit, Tempest Spine, Chains of Flame, Restless Isles Slayer etc. etc. etc.}. Players shouldn't have to go to the wiki for a working map!