Hi all.
I am trying to make a magical sword with edge of razor and blade of virulent flame.
But what will the final damadge for the sword be when both spells is in effect?
Normal Sword:
Init: 2 Atk: +4 Dfn: +1 Dam: +6
Sword with Edge of Razor
Init: 2 Atk: +4 Dfn: +1 Dam: +6(+2)
Sword with Edge of Razor and Virulent flame
Init: 2 Atk: +4 Dfn: +1 Dam: +6(+2)*2 = 16
or 
Sword with Edge of Razor and Virulent flame
Init: 2 Atk: +4 Dfn: +1 Dam: +6*2+2 = 14
+16 og +14 in damadge 
Without reference to rules... I'm inclined to be generous.
Id say +14, as it would feel odd to add exta fire damage from making the edge sharper.
and I would say +16. The sharper edge means sword goes in deeper and so can burn more flesh.
It generally does depend on the nature of the effects. Sometimes it would be one way (add before multiplying) and others it would be add after multiplying.
For example, if it was 2 pts poison and double for flame, I would say +14 since fire is not going improve on poison or poison improving on fire. This particular case though the sharper edge means it cuts in deeper so flame reaches more flesh (thus doubling after the sharp edge bonus).
I like to count it as "adding the weapon's damage value a second time". So it would be 6 +2, +8 for "adding again", = +16. So if the target has a +15 soak versus fire (or is immune), he still takes the full +8 from just the sword, but if he has say only a +5 soak versus fire, he still takes +11 (8+3).
And I agree with LadyP. If it cuts deeper, the fire damage inflicted is more sever because of deeper penetration (in the mundane sense) and greater flesh exposure to the fire. As for the poison example, I also agree. The flaming blade damage is bbased on the damage of the blade itself, not extras like poison or acid.
Personally, I'd have preferred "Blade of Virulent Flame" to have had a fixed bonus for the fire, although the burning greataxe certainly has a lot more fire than the dagger.
I'm inclined to only double basic damage, and add any other modifiers, like for quality, Edge of Razor etc. afterwards. YMMV.
I would and do count the razors edge bonus for the Virulent flame and call it +16 , but it could go either way so if my SG decided on +14 I would not complain (Much)