Ive bombed alone on 99% of my bomber sorties. There is only a small fraternity of bomber hunters in this game I even worry about, and I know its one of them by the way they set up for an attack run. I dont even worry about multiple fighters unless its 3 or more attacking at the same time. And I personally dont believe in climbing that high, 14,000' is tops for me, cause you miss out on shooting down to many fighters.
For months I would start up every game day by a sortie or two in the TA. I'd post a comm message, "go ahead and attack the bombers taking off N/E from A1", and I would practice my gunning on real targets making real attack runs. It will get to the point to where gunning comes 2nd nature to you. I also suggest flying fighters against bombers as well just to get an idea what the fighter stick is actually seeing.
And buy separate foot rudders. Small adjustments in course can screw up an IB fighters attack profile.