AppleRemote & AppleDock modules

Little question, though: using eith 8 wires or I2C is mandatory to have quicker response between lcd.clear() & the next lcd.print call ?

I believe the module is just as quick in 4 or 8 bit mode...

I think from what you are asking - you are getting a flicker on the display?
Instead of using clear just set the cursor location and over type the characters use ' ' to clear a single char.... Then you won't get any flickering