API_GetFactionInfo has been replaced by API_C_Reputation.GetFactionDataByID and therefore this doesn't load on Patch 11.0 and higher

Warbands can partially share quest progress:
C_QuestLog.IsQuestFlaggedCompletedOnAccount

We Also need to keep in mind that there are 3 types of quests: Sidechains with a normal golden icon, campaign quests with a strong border around it and "important" quests like for the Pandaria Remix that have a purple diamon as icon.

We have more quests and questhubs shown on the map now. Check for Quest and AreaID/POI changes mentioned here:
https://warcraft.wiki.gg/wiki/Patch_11.0.0/API_changes
@smaitch

The addon is almost done being updated to work in both the 11.x releases as well as Classic and Classic Cataclysm. The new types of quests are not handled differently as of now, nor are any new quests added. Things like that will come as time allows.