Mnnn - not sure I like the way that the template css is handled - with the import calls linked back to the base template - this is an unnecessary dependency and additional overhead that should be avoided. Also, from memory different browsers handle style overrides in different ways - this is encouraging problems!!
I can understand the philosophy of including the base template so that future upgrades do not break site layouts, however, this will happen in anycase to a heavily modded site. Fixing see more template / css issues is an accepted part of updating / upgrading that is easily handled if a proper changelog is provided and new additions to the templates follow the css structure. Most new mods / items can probably inherit existing css class attributes - therefore no changes to css are necessary and the upgrade does not break the site!!
I would like to see the dependencies to the base template removed and there to simply be one template - I.E. get rid of base - move everything across to UNI (or vice versa) allowing people to simply copy the whole directory when they want to make another template.
Additionally you can also read the directory name to auto generate the template name - so no additional mods are required to make a new template other than simply copying the directory. EASY_PEASY
That said - it is 200% better than the previous way of handling the templates (with the compile required). It just still leaves that little bit to be desired.
Don't over-complicate things by trying to make it clever. It doesn't need it.
If you want to make it more user friendly - add a function to the admin panel to create the new template (by copying the base template)
Add an editor for the html files too (same as for css files).
Now you don't even need to open up an editor / ftp client to do stuff.
I can understand the philosophy of including the base template so that future upgrades do not break site layouts, however, this will happen in anycase to a heavily modded site. Fixing see more