In one post you say that you are planning to connect MOSI and MISO to the SCL and SDA pins Arduino Pin A4 A5 and in another that you never said that you wanted to bridge A4 A5 to the MISO and MOSI pins of the ICSP header.
They cannot both be right
The bottom line is the thread was not adequately clear from the beginning, and there was a lot of speculation. Still not very clear.