That last part you could already do by building your hangar above the lift, general stores below and then (ten days later) everything around the GS. Aliens only ever come in through the hangar and lift, so there's your bottleneck right there.
Yes, agreed to that, and to the fact that nothing much needs to change.
But just so that we are clear, Firaxis: no research, no base building = no buy.
For all this 'Actual New Games of 2012' nonsense, deep down I'd settle for a zippy looking UFO which didn't take ages working out what to do when there are still loads of enemies left alive.
Also, we should still be able to separate the main part of our base from the hangars via a single 'lift' tile so that we can contain base invasions easily.
Persistent multiplayer, or some kind of deathmatch would be awesome as well.
LB, you really are a massive geek.