From my experience and my game choices...
I prefer only 'full real' with no icons/labels of any sort.. now for the tactics..
Qs 1-2 are already answered.
3) A little knowledge/reading helps :-
- tracer colours
- aircraft shapes
- common tactics (Axis usually BnZ, Allies TnB - but this is not the rule)
- and the obvious statement = practice until you can do it blindfolded
In game:-
- Every bogey(unknown) is a bandit (enemy) until proven otherwise.
- In a multiplane engagement 'attack' the a/c that's attacking another, until you can visually ID the attacker.
- Try to keep your advantage so that you can return to your 'perch' if your target is a friendly.
and for your virtual survival..
- Practise flying your a/c in any situation, the best place to do this is with QMB (Quick Mission Builder).