I just want to complete this project to start using it. And write a post here about it.
Due to interrupts and clock limitation (also I tried and tried but could not make the two codes into one), the project ended up using two arduino chips. Each connected via serial. One emulating the USB Keyboard and one with the ethernet and IRDA. All this might be able to be resumed into just one arduino UNO board with a different firmware for the usb to serial chip and might look actually better and smaller.