I have a list of, IIRC, 900ish air-to-air kills by Mosquito fighters. It most certainly was used as a fighter as well as a bomber, PR and strike aircraft.
Closer to 1400 by my latest count - hope to be able, over the course of the next few years (that's how long it will take) to be able to split the confimed from the unconfirmed. By contrast, about 160 Mossies were shot down air-to-air, including some I suspect to be friendly-fire, which is another little sub-project...