Honestly, as more 1944 and 1945 fighters such as the Ki-84, Bf109G-14 and Spitfire Mk XVI have been added the Mosquito's odds of survival have been going down. I found that the change from AH1 to AH2 had a major negative impact on my ability to be successful in the Mosquito. I think it was the change in the hit detection model that encouraged greater use of fast fighters such as the La-7, and those are the best tools to kill a Mosquito.
All that said, when using the Mossie as a fighter, remember that you are a fighter. Be aggressive and don't be afraid to take marginal shots. The firepower can pay dividends on them. Generally I would come into a combat area at 13,000ft, the Mossie VI's best speed altitude, and use that energy to keep your ability to manuver aggressively and kill fast. Watch your E levels and keep your SA up and you should kill more than you die. The Mosquito will not get you kills or a K/D ratio like an La-7, P-51D or Spitfire Mk XVI, there is a reason it has an ENY of 40, but it can be a fun challenge. Only use the cannon unless you are out of 20mm ammo (yes, I have scroed kills with just the .303s), turn tracers off and set convergence to 650 yards. Never take more than 50% fuel.
Even in AH2 when I was having an on night I could really get some use out of it and successfuly mauling single engined fighters in a big brute like a Mossie can be carry a very rewarding feeling.