11. & 13. are the similar. I'm not sure if it's a required step. Although in 13, 32-bit and 64-bit is doing the same thing.
No idea why 13 is there, it's already done in 11, and yes, the 32 bit version is wrong in 13.
16. is really confusing is it right? I'm not sure. And I don't know where everything goes so yea... -.-|||
No, its supposed to be like that, although I prefer this version:
sudo sh -c 'echo "/opt/ati-stream-sdk-v2.1-lnx64/lib/x86_64/" >> /etc/ld.so.conf.d/local.conf'
sudo ldconfig
Also, the 32 and 64 bit versions could be grouped better to avoid having so many "do either this or that" lines, and some of them could be done in one line using wildcard for the 32/64 part. Regarding all the echo lines, it's possible that people aren't in the home dir when they start. In that case it will fail miserably. Use ~/.bashrc instead just in case.