I've a similar setup running oe7 but saw that your trying to intergrate retro arch so thought I'd give your build a go.
Had a thought about channel updates. Why not stick the tvh and vdr files in a bit of free webspace and add links to the openelec folders and the webfolder in file manager. That way people can just copy the updates direct.
Same could work for the updates folder. Or using the Dropbox plugin. Did u get e22tvh to convert the numbers properly?
I gave up with it and just did it manually.
Ps thanks for the build. Will post results tomorrow. I can send u my bouquets if u want as well. They are converted from autobouquets