Hmm... the Runes of Magic user interface looks interesting. Nice and clean. Some of your requests aren't possible to modify but in general the RoM user interface could be replicated.
Several changes you can make yourself using the default user interface. You can move the quickslot bars yourself by unlocking them (options --> quickslots --> uncheck "Dock Bar X") and moving their location (key mapping shortcut for "Reposition UI"). You can also scale the quickslot bars yourself (options --> ui settings --> ui settings --> "Quickslot Bars"). The buffs and debuffs are attached to your character's vitals window. It's possible to create a custom skin to remove them but you might want to look into using one of the LUA tools like
BuffBars to display buffs/debuffs.
Moving the toolbar buttons to the bottom right can be done with a custom skin. What do you mean by "no artwork on the quickslot bars"? Do you mean no placeholders at all? Just the skills floating in space? That could also be done with a custom skin. You already know you can change the hunter focus bar like in the example you linked.
Hopefully that gets you a little bit closer to the ui you want without messing with any xml files and graphics.