2.) AMD VLIW architecture requires that you optimize stuff in the driver || nVidia before kepler do most at hardware level so is somehow a bit easier
3.) you have C++11 API documentation, what is stopping you in writing a kernel using advanced C++ techniques and objects?? you have the API documentation LOL are you shy?? documentation analogy
4.) AMD documentation is about GPU ASM/registers API NOT OpenGL X.x for GPU newbies, so no it doesn't tell you how to blend 2 YUV formatted texture attached to an model in a 3ds file at 850FPS LOL in the same sense that the CPU ASM API don't tell you how to write Libreoffice. Dont trust me go and download AMD docs (i expect someone post after read this "LOL AMD sucks it only give ASM docs, WTF??? they hate linux OMG") <-- i will laugh like crazy
5.) Have you tried to run you GCN card in FreeBSD? it won't work right? cuz BSD graphic subsytem is LOL and ancient right? well that was linux graphic stack genius, so ppl arent only writing drivers PPL the problem is they are writing the entire graphic subsystem alongside the drivers at the same time, which is even harder to do.
Microsoft did this too from old XP model to the new V/7 model and it took them 10 years to get it almost right