3) well cheap is very relative, but compared to TVC engines and a larger variaty of foreign sensors and equipment, you are probably right. About the engine, they probably want their own engine for the full series production J-10, otherwise Russia could 'limit' J-10 production if they want. WS-10 was reported to be the Chinese engine, but I wouldn't be surprised the development would fail.
5) not really worth mentioning here I suppose the MKI's maneuverability would be better with the TVC and canards.
6) don't forget the airframe and gear strengthening for heavier loads.
The good thing about the MKK, is that is has been followed by the Su-30MK2, a more capable maritime attacker, and will most probably be upgraded to Su-30MK3, as well as new built Su-30MK3s.
1) Well you can't just install canards and TVC without upgrading the FBW control. In regards to how more digital this one would be, I don't know. China plans for the Su-30MK3 specs call for upgraded the FBW control system. So until then Su-30MKI's system would be better I suppose.
5) Phazotron N011M I think it was, which would indeed be superior to the N001 derivatives of the Su-30MKK, but China is looking at more advanced radars as well. And how many N011Ms have actually made it onto current Su-30MKIs? I am not too sure.
6) the MKK got a refuelling probe as well, but you say modified, I don't know about that. Anyway, I doubt the modification made it significantly better.
By the way, on this page: http://www.milavia.net/aircraft/su-27/su-27_specs.htm
I published some specs. However the source suggests the internal fuel of the Su-30MKI being larger than normal Su-30, whereas the MKK would have the same. I suppose this should be the other way around! Since the latter got the increased area fins (which house fuel cells) and was modified for extra loads. So I am pretty sure Su-30MKK should be larger than 9400. Anyone have some data on this?