Access to remove the old lightswitch gets better if you remove the end cap of the dash first. Then at least you can kind of see what your doing on one side, and can push a little on the back of the switch. As for the new switch without front fogs i suspect the circuit board inside will be missing the green indicator led that illuminates when the fogs are on. At least that what i found out when dismantling a switch with only rear fogs. The backlight in the fogswitches and adjuster wheels are done by a normal bulb on the rear of the switch unit, but the indicators for foglights on (green and orange) and the light in the light switch itself are handled by three leds on the circuit board inside. Switches without front fogs will most likely be missing the green led for them to.
Edit: just remembered that fl omegas may not have the green led in the switch as the pfl has? But a symbol in the dash instead? Never owned a fl. If thats the case and your car is a facelift then ignore everything i said:p