Hmm, I do like the idea, but I'd have to find a way to give a better balance between the two. The +10 things would probably come from activity checks (If I did this on a monthly basis), or those who make it to wars (When we have them).
I'm thinking of doing something along the same lines as the in-game thing. Find two variables, but give one more sway over the final score.
0.3(Total posts) + 0.7(_______) = Forum score
0.3(QI) + 0.7(Win ratio) = In-game score
Forum score + In-game score + Extras = Total score
I could cut the in-game and forum scores in half to keep it as something out of 100, but this seems to balance better. Plus the extras would be worth quite a bit if I did half of each.