[Imp]

Firstly I agree with Mobhacks assesement air is risky on the whole if facing a decent enemy arty gives better bang for the buck. I use fixed wing only for atmosphere or if given a fair amount of sorties. Used to hit my own chaps fairly often but last 5 years have hit my own troops once maybe twice. Its simple really remember you ploted it & dont put units along the flight path. The only planes that can act a bit eratically in my view are SEAD aircraft that have used all there radar seaking ordanance & still have regular weapons left, on occasion they just dont seem to fire.
No expert but watch vids on you tube strikes are called in a longway off if for nothing else to stop getting hit by debris & there are several vids of freindlys bricking it when an A-10 decided to take on a target of opportunity. Its not as cut & dried as it looks things dont work as well on the battlefield as on paper.
As to being able to select a target nope apart from possibly a hex with a building in it even now I would say its not as easy as you think, planes are best used to attack easy targets like buildings & convoys because of this. Take the Iraq war & whatever that commanders quote was "Survived 7 days of air attack for the loss of 3 tanks & lost my entire brigade in 5 mins of tank fire" Ohh didnt the planes do well & that was in the dessert so good visibility & vs none or outdated AAA.
As to your point 2 what weapons are not as leathal as they should be? Possibly modern programable anti personnel rounds fired from tanks & IFVs but the firer has to be stationary to use it & game engine cant differentiate or do over the slope fire. Maybe possibly GL a fraction more leathal but needs right terrain.
Again stuff does not work as well on the battlefield as you might think, look at the ratio of rounds fired to somebody actualy getting killed esp if your talking the simple bullet, thats why infantry battles take a while in SP.
And on air sometimes they do wonderfull things I had a SEAD arcraft (cant remember what) on its pre plotted attack kill 2 SAMs & as it turned out my opponents FOO vehicle in 1 pass, It could not have found a better secondary target.