On "Govern" -> "Kingdom Report"-> "Master Quest", the last line reads: "The quests are Epic level and will require a powerful army to defeat." I don't know that you can "defeat" a quest, "complete" is better even though it is used in an earlier paragraph.
In my most recent game, I was able to cast the spell of making while still building the Forge of the Overlord. I would expect that this spell can only be cast once the Forge is complete. If you win the game on the same turn that a research project completes, the research dialog appears but the normal "Done", "Close" and "Cancel" buttons are unresponsive. There is no way that I have found to close the modal dialog. The only solution I have found is to ctr+alt
Right now, when you have a party selected, you have multiple options: "Equip" and "Trade". Instead, there should be a single option "Inventory" or something similar. You should be able to easily cycle through the inventory of all units in the current party, equip and unequip items, and trade items between party members using this screen.