OpenCL support is being deprecated in COPRTHR 2.0. It has been discussed at length on the forum why it is not a good programming model for the Epiphany architecture. I am not the developer but you csn always email him directly.
You might want to try out 2.0 since there are many good features. Many of the things you mentioned are already there. Others aren't so obvious. For example, you may want initialization code that is large but only called once to run out of shared DRAM. The tools for binary analysis are there and will enable you to control code placement better.
If you like having the OpenCL data types and functions, you can always pull in that header from 1.6 for a hybrid programming model. I do have a more complete version of it if I ever get around to releasing it. Many of the math functions could also be incorporated into the PAL library.