I guess you need to find a balance.
I agree with FAST and the OP: doing a home-made text dump that isn't usable for re-insertion, and translating the whole thing, is pretty much useless. Pablitox has had all the trouble in the world trying to get a translation he has matched to something that can be reinserted, so he can talk about it...
On the other hand, agreed: it is easierto feel appealed by existing translations than by "hey I need help" messages.
So rather than being extreme on the need to show a passion through the translationof the whole game, I'd ideally suggest the OP to choose a "good chunk" of the game (I'd have said a mission for a turn-based strategy game, for instance)and translate that chunk of story. That will show your style, how good your English is, and show there's work done.
I would suggest to refrain from dumping the whole script yourself (whether by youtube watching or whatnuts).
I wouldn't ask to show you can fit into technical constraints. That (for me) comes as a second step.
Also, with regards to rules on this site, I think Japanese-to-Western-language translators are too few and far between not to try and ease thei finding a match in the community. But that's up fo discussion I guess.
Overall, dear mariosmentor, don't give up just yet! Translate a few pages, start sharing around, then something may happen and you may meet "the right person".