Could get a little tiresome - there is a fine line between overcomplicated and and realism IMO.
Other craft do it already in FE2/FFE while launching. Besides, proximity sensor should be back - I like ambushes and all, but it's not like you can't see intercepting craft in deep space from good several thousand km - being alarmed when there is another craft within 100-200km radius seems reasonable and would give you the time to raise the shields. It might allow for interesting mechanics, for example you might want to keep your shields down when approaching a trader, as doing so with your shields up would be rather obvious hint that you're up to no good. There could also be docking with other craft (for various reasons - trading, rescue missions, boarding, etc.) which would be interesting if it required shields to be down. Landing should also require dropping your shields.
It gave me another idea - cloaking systems, which would require shields to be down and would have to be deactivated prior to firing a beam weapon.
Other than an 'aesthetic' addition I'm not sure what advantage this would have to the gameplay?
For one, it'd make multi-seat craft feel truly multiseat. It'd be much better if my second crew member in Asp was able to pick off the Ospreys from my six while I'm busy piloting the damn thing, and, to do so, non-fixed rear gun would be necessary. Same with larger craft, they have turrets *and* multiple crew members. Of course, Cobra Mk.III would still have fixed rear gun, as you'd have no one to fly it while firing your rear gun, so having additional set of controls for aiming would be impractical.
Another thing it would allow for, is differing skill levels for crew - what's the point of asking the guy if he worked on a spaceship before, if all he does is consuming your credits?
Lastly, it'd allow for different behaviour of AI craft - for example, Cobra Mk.III would never fire both guns at once, while Asp with veteran crew would be able to go after you with it's main weapon, while trying to shoot the missile off it's six with it's rear gun.
What I would like to see is the mounting of multiple turret weapons on the larger ships and then a combined focusing system where you can fire several at once against one or multiple enemies.
That'd be cool, same with more divergent selection of weponry (mass drivers anyone?) and multiple forward firing weapons on larger ships (say, two for Viper and Cobra, three for Asp, four or five for the IC, etc).