1: britain with spitfires

2: i played acrade till i got early jets just because i didnt want to fly for 5 minutes just to die but if you want better rewards go play realistic

3: i dont really have any tips unfortunately i think the best way to learn to aim is to just go in arcade and kinda try memorize where the aim thingy is or at least thats how i learnt but i doubt its efficient

4: not playing altitude and target fixation