Fire/Force is very strong, so is Fire/Ice and to a lesser extent Fire/Light. I know your friend suggested it but you shouldn't let him decide your build. I love playing with Fire/Force archers but maybe you like to be more tanky or speedier
Anyway Light/Force is not really an option for a pure str char, I don't know how tough sp farming is on your pserver but getting the sp for the few Light skills you're going to use is not worth it. Besides that you can easily cover the main part of Light (the speed) with potions just as Mayumi said.
As for grinding, your debuffs are rather useless. They never hurt when you're fighting a giant or any pt mob though, but no use in wasting them on regular/champ mobs. The stat heal is nice if you don't want to spend money on pills and the ring is good if you have trouble in higher lvl areas but all of that is optional.
If you do decide to go with Fire/Force and you have questions feel free to pm me. I had a lvl 100 on iSRO before I left ^.^