Done some mining from WhoHas and PeriodicTable.
I know you're busy with the localizations, but if you have time you could look at it :)
The attached file contains the tables with the data I thought about showing.
The gathering part could be used somewhere at the tooltip hook.
(if GetItem returns nil you could search the id in this table and show information about that item)
The crafted item information is a simple id -> ids dictionary.
It could be used both ways for getting crafted item(s) and source item(s).
The reputation turnin part is a bit hacky (added them to the loot tables)
But at least this one already works for me. ;) And you can extract the item ids from it, if you want.