Thanks very much for opening this thread!
Information about using openelec on the c100s is quite rare.
So far i'm using the box with the original firmware with a monoblock astra/hotbird lnb.
No serious problems but i would like to have the comfortability of OpenELEC.
I followed your description but i couldn't find any kernel so far which would show me any wifi connection.
Hopefully someone will find a way to fix this soon.
I also replaced the system with openelec 6 but it stops booting when the logo is coming up!