Battle

The default monster sprite should not be set to frame 0 but to the first movement animation index instead
Use animation alternate bits for monsters
More flames when being hit by fire spells
Vanishing of wind spells looks odd in some cases
Initial scale of dissolve victim has bad anchor behavior if in front row.
While a monster is hurt and moved (wind spells) it shortly changes the frame index back to normal which looks strange
There are other animations in monster data, maybe one of it is the "get moved by wind spell" animation?
In rare cases (I guess if two party members are killed with one spell in battle) there is a part of the head below the skull in the portrait area

3D maps

3D monster get easily stuck on wall edges.
With graphic filter on and fading, elements in front of the 3D view are semi-transparent. For example when entering Grandpa's cellar for the first time you can see through the popup.

When changing the battle speed etc by key and hover the option in the list, the text is gone
Triggering a yes/no button by key takes very long to execute the action
Save the scroll offset for save/load lists
Giving items per cheat to a char but have another char's inventory open, shows messed up item amounts.
When closing the spell book with RMB in battle and there is a battle actor behind the window, the inventory is opened afterwards.
"Do you accept this character?" message is missing in character creator.
Question about taking items with you is missing from conversations. At least for non-essential items.
LevelUp popup while an item is given will draw that item in front of the popup.

Teleport cheat can teleport to non-blocking map areas which are "outside" the map borders. For example map 344 (Ferrin's forge) has many areas that are considered outside the house.
Where is the text "CannotCarryAllGold" used?
Check all unused DataNameProvider texts.
When leaving a map through a teleporter and there is an engaging monster, the attack might occur after the map change. This must be avoided.