je veux faire ca parce qu'il faut mordre la vie à pleines dents pendant qu'on a des dents avec lesquelles la morde
Haha that's a great turn of phrase! I think this would be fine IN CLEAR CONTEXT because it i) fulfils the cultural language component and ii) is pretty clear and unambiguous. If you do use this sort of thing though, use it
sparingly and
correctly otherwise you'll look a bit silly.
And I agree in part with Travis, have a bit of banter with the examiners because they're more likely to mark you favourably if you liven things up a bit for them.
P.S. Never, NEVER ask them a question in return. People have done this in the past et ils ne la regardent pas favorablement
du tout. The setting may be conversational but it's important not to entirely forget that there are expectations and criteria to be met.
Alors, je pars bientôt, donc meilleurs voeux (à tout le monde!) pour demain
