Star Wars Rogue Squadron 2: Rogue Leader

Didn't Biggs and Wedge join the Rebellion before Luke? So why does Luke order them around during the death star attack? This was seen in the movie also. Luke is Red 5, and Wedge is Red 2, yet Luke takes over as leader of Red Squadron after Red Leader dies.
The B-Wing is supposed to specialize in taking down capital ships, yet I find it easier with an X-Wing to take down the Star Destroyer in the Razor Rendezvous mission. As a matter of fact, I find it difficult to beat that mission without losing a life while flying the B-Wing.
After you defeat the Star Destroyer in Razor Rendezvous, it crashes into the planet. Yet in the next mission, Vengence on Kothlis, when you reach the Star Destroyer the gun turrets still fire and it somehow deploys AT-ATs and AT-STs. How could anyone possibly survive a crash like this in order to operate all this stuff?
During the night version of Imperial Academy Heist, there is a TIE Fighter that you can use and it's located in a valley. However, if you fly too high, the sensors somehow pick you up. Odd thing is, there is a huge mountain between your snowspeeder and the sensors. I know Imperial technology is superior, but how can it detect through solid rock?
Why did the Rebel fleet bring a Medical Frigate with them to the Battle of Endor? It can't take much damage; it doesn't have as much firepower as a Mon Calamari Cruiser, and how are you going to find time to send your wounded over to it in the heat of battle?
If you pick the Milennium Falcon in the last mission, Strike at the Core, then you become Lando and you must protect Wedge who flies his X-Wing. However, if you pick it for the Battle of Endor, then you fly as Wedge and you can see Lando in another Milennium Falcon ahead of you. How can there be two Milennium Falcons?