Would it be possible to add some features to Automatic Timescale:
When in a city
When in a cave/Ayleid ruin
There isn't really anything that says where the player character is. There are mods that try to check this by determining what kind of meshes are in use, etc. but they're not foolproof. So that's why I haven't added anything like this.
When sneaking AND running
Yes, that is easy to add.
The option to have the timescale while in combat be a multiplier (eg. 0.5 for halving the current timescale)
This is also easy to add. To understand you correctly, if you have the timescale inside to 16 and sneaking timescale to 10, you want combat timescale inside to be 8 if not sneaking, and 5 if sneaking - instead of a separate combat timescale as there is now?
Do Display Stats and Quest Log Manager support DarkUI, the original?
No, they don't. I didn't think there were many players that use the original DarkUI anymore instead of Darn'd DarkUI.