Is this really a good idea?
Well, yeah, it is.
However, if you translate the demo to a certain language, the full game ALSO has to be translated to that certain language. Or else, it'll be like giving a kid a lollipop, letting them suck on it for one minute, and then taking it away from them. Poor poor kid... Is everyone prepared for this?
I hope so.
As for a language...I'd say Japanese!! But, I'm not fluent in it at all. Lol.
As for translating jokes...not all jokes can be translated to certain languages because I'd think not ALL languages utilize sarcasm or even know what sarcasm is. Like, if a foreigner listened in on an English conversation using a lot of sarcasm, they'd think something completely different was going on.
And as for translating into some languages...does your text parser parse unicode-encoded characters or just ansi-encoded characters?