I wouldn't use the EasyTransfer library in your case. It only makes things more complicated and I don't see the need for dynamically sized transfers on the I2C bus.
Ok.. I suppose it's best I understand the I2C basic methods, especially to work with devices not-as-smart as Arduinos. I was hoping to use EasyTransfer as I assumed I would be able to more easily change data types and sizes without having to bit-bang the changes through... perhaps I'm over thinking!
My confusion is centered around this thing you're call a "register based approach". The theory is clear, but the implementation eludes me. I feel like I'm asking to much for your to hand-hold me through this, so I wonder if you could recommend an online resource for I2C, or other resource? I suppose I need an I2C primer which is more in-depth than the Arduino references.
EasyTransfer (imho) still feels like the right, more dynamic solution for communicating to the web-server slave... do you foresee any problems using them together?