Like some of the others, I also disagree with the others about removing mobile support. Cross platform support including mobile and web support is one of the best points about Urho, if you ask me (and probably the reason the complex build system is required, and also one of the reasons I personally use Urho). While I personally don’t really care about 2D support, it is there already, and should at least be maintained since, as far as I can tell, it is pretty solid.
As to the scripting issue, personally I would favor removing the requirement to add script bindings for contributions. Given that the scripting API is already incomplete (deliberately leaving out low level stuff) and inconsistent (e.g. there are AS bindings for PackageFile but there are no Lua bindings), I would favor asking that script bindings be included in contributions, but if they are not only requiring that an issue be raised requesting them for the new feature. Perhaps also we could require that script bindings be maintained – if you change something that breaks script bindings, don’t just get rid of the bindings but rather fix them, or include new bindings if the new functions/properties closely relate to existing features if it is easy enough to do. I don’t necessarily think that should be a hard rule, as if you introduce Vectors the bindings can get very complicated, but neither should we allow you to add some integer to a class that is exposed only to the C++ api, when it would be one additional line each for the AS and Lua bindings.
I will say I definitely oppose removing scripting support from Urho. While that would ease maintenance, scripting is excellent for a number of things, most important of which I think is dynamic execution of somewhat complicated behaviors for things like item actions or NPC behaviour – I want the NPC to say “blah”, walk along some arbitrary path, push a button, and then say something else. Or the even more simple conditional execution of speech – if some condition (like a global flag) has been set say “X” otherwise say “Y”. On a less-globally-useful note, scripting is also a much better way to support modding of your game – reskinning it is easy enough without it, but if you want to allow new items with interesting effects and such you either have to have a very complex class for the items in C++ (like Urho’s Material class, for example) to allow all of the needed behavior on the C++ side based off of the stored data, or you can have a much simpler class that defers the important behavior to the scripting language.
On the other hand, I don’t use Lua at all (I have no interest in learning it’s strange syntax) and pretty much only like AngelScript because it is so similar to C++. I would definitely be open to other scripting languages replacing them (python (which I like, though I don’t know how nicely it would fit as a game’s script) or C# (which I’ve never used) perhaps, though the latter especially seems rather heavy for just a scripting language for your game)…
Regarding your comments about “Shaders/Techniques/Materials”, I definitely agree that these are complicated, but I also feel that it is out of necessity. I think think the solution would probably be better documentation/tutorials (they needn’t necessarily be included in the documentation), though at least for Materials I feel the Editor’s support may be enough. As to writing new shaders (and then accompanying Techniques and possibly Materials), this is indeed a very complicated topic and I’m not really sure how you can make it easier (docs/tutorials?) since what they do is complicated and, from my experience at least, writing shaders is a much harder to debug process than C++ code.
Regarding the Editor, I also think some definite improvements could be made. I think the simplest would probably be to have a default start-up file like Blender that is a really simple working scene (possibly a clone of Blender’s – a model, a light, a camera, and then a Zone with a not-black fog/ambient color (I don’t like the black appearance, and I don’t like having to add a zone myself to add ambient lighting whenever I want to look at some models/object prefabs. However, I also agree that it is good that Urho is "that Urho is not an ‘editor-first’ game engine,” especially since I use Blender as my editor for both models and scene layout.
Also, what program did you use to obtain the stats? It looks similar to the output from cloc, but it’s different enough that I think it must be something else.