Hiya mate.
Some missions spawn with the brakes on and you have to dab the brake button to unlock 'em. Make sure you have a button on your joystick assigned to 'toggle wheel brakes', and just make a habit of dabbing them each time you spawn. The nosing over on take-off is something that happens even to us old hands if we're not concentrating. It usually means you're going a bit too fast. Try holding very slight back pressure on the the stick, and as the tail comes up holding it, and you should lift off naturally at about 85-90mph. Hope this helps.
P.S. the difference in pitch control is that you are now in the 'constant speed' Rotol prop version, which is actually much easier to manage. For take-off have it in fully fine pitch, with rpms at 3000 for take-off. As soon as you're up, and the gear is up, dial it down to around 2600-2700rpm, set radiator at 50%, or 'normal' if you look down and to the left at the in-cockpit indicator. She'll fly at these settings fine until you run out of fuel.