Too many people

I agree, but how do you deal with a 600 year time lapse? Everything mundane is literally erased from your entire experience up until the cryogenic pod opens up. I can see someone getting a wild hair up their ass and declare mutiny or even worse... a Cerberus sleeper agent ready to create havoc for the other alien races. I could see chaos occurring because 600 years into the future... anything goes. 

If you are going to do something like this, you are going to know this, its not as if you would do it without knowing to be asleep for 600 years. I am pretty sure they had some psych profiles done first, long before entering cryo. Also, you have AI personel... it is even said in game, AI personel was handpicked and is brought out of cryo, not the regular colonists, who expect to wake up and go straight to their new colony. Tann is 8t in line, which is still inner circle and stable to do the right things under pressure. Whas did they told us? Exiles did not want to go back in cryo and wanted to wake up more? Like... for what? Nexus is hit by the scourge, so reactor core damaged (assumption, as they are happy to have the Hyperion core), ressources are thin, the golden worlds are found out to be everything but golden, no/low energy, large partions of the Nexus damaged (hydroponics), food/water is low... and they want to wake up more, so... when the rations are not enough for 500 people, it will be enough for 10.000 ? What are the exiles thinking? What if they won? Wake up more? And then? THe Nexus folk know about the Kett, but had no idea about Kadara, so basicaly, they would load shutles as they have no other spaceships and fly out into the unknown, aboard a few hundred shuttles. Now that is a plan that guarantees survival.
Edit: I think this whole "uprising" plot serves only the purpose to have a third faction in fights and some pirates and outlaws.

Boom! Goes Wrex's shotgun. You're right. 

Wrong.

Wrong.

Correct!

I'm not trying to be a douche. (Seriously.  )  I just think it's humorous how wildly these figures vary. The 100K total figure is stated by Alec Ryder in the opening scene, and reiterated repeatedly.

Speak for yourself, my favourite race is the Geth. 

I feel like BSN is running out of things to talk about or at least complain about.

Yah, but despite of this... I did play, finished the game, and at the end I could says: hm, I would have added this and that, would have changed this and that. But basicaly, I had fun playing the game, destpite the plotholes.

And MEA? Every second or third scene I think: why he hell would they do that? Why would they DO that? Why would they do THAT?? Having ideas how they could have improved the scene in the second they happen...

Eh.  I'll grant you there was some stuff that was off in ME:A.  I still think that ME2 was the absolute worst offender BY FAR of the Mass Effect games in this regard.  Even with as much as I hated some of the plot stuff in ME2, I wound up enjoying the game.  I had to damn near turn my head off to do it, but I don't regret my purchase overall.  ME:A, while certainly not lacking in this kinda thing either, didn't force me to turn my head off NEARLY as much as ME2 did, so I'd say it was an improvement.  

You're more than welcome to disagree with me, but I'm right and I know it, and I'm comfortable with that.   

Now,if you started out as the human pathfinder and Alec Ryder went with the Nexus, however on arrival you discover he has been murdered along with Garsen, making you "Pathfinder Prime"....now that would pique my interest!

I don't know if you read the book, but almost, if not all, were released from cryo during the uprising.

They do have all that. Or did. They had the scientists where were there to do deeper studies on whatever pathfinders might send their way. A militia of sorts once the original security team lost their leader, but they're there to secure the Nexus. Honestly, you'd think they'd have more to have to protect colonies. I do agree that it was incredibly naive to think there would be no hostile activity on arrival just because the AI has peaceful intent.  They still have engineering.

Exploration was supposed to have been left to pathfinder teams. Everyone else on board the Nexus was to study and do R&D with whatever pathfinders found in their travels. I think it's a bit strange that the pathfinder can do his own R&D on that tiny ship with all the resources required, but it's something I've been overlooking.

The game also explicitly states that the whole intiative numbers around 100,0000. People just don't listen.