The nose wheel steering has been adjusted and, to me, is an improvement. I'm pretty bad at taxiing anyway and I would rather that it can take off and land well.
Tip-trails, g-force/condensation etc are just eye-candy things that are not that difficult to 'import'. But bear in mind that this is not anywhere near as manoeuvrable as an F-16
I have masses of stuff that has not been incorporated into this (yet). Whether or not that gets used depends on the interest in it. The DCS version of this is indeed a very good reference - I have studied it extensively