A lot of people tend to call ideas from the prequels "stupid" just because they came from the prequels.
Of course it's still historically canon, but the idea is that future versions of "Sith" or Sith wannabes would have the option of dispensing with it, as was seen in the Legacy comics.
Regarding Finn: Does anyone else suspect that he (and many of the other new stormtroopers) might only be 10 - 12 years old? Maybe it's just me, but something about the way Boyega is playing the character - and how young everyone in the First Order seems to be - makes me suspect that the stormtroopers are being accelerated in aging to maturity.
^ It depends on whether the First Order already existed in some form in some far corner of space, building up their forces and biding their time for quite a while before Ben went Berserk and Luke went off into hiding. Kor
The impression I got is that the First Order abducts young children and indoctrinates them into stormtrooper life. After all, Finn apparently remembers no other name than his serial number. So if we presume Finn was in stormtrooper training since he was very young, the stuff we see of him in this movie is basically the first time he's interacted with the "outside world."
RL training or virtual training? Clones are given massive amounts of information directly into their brains while they're in tanks maturating at an accelerated rate. Why not stick a 10 year old into a clone tank, speed up his or her growth rate and pump his or her brain with Stormtrooper programming, so that 6 months later they look 20, and have basic training and a first class education in any thing necessary to be a storm trooper. Maybe the reason Fin doesn't remember his life pre First Order is because of the 100s of terrabytes of data about installing toilet mains that has flooded and submerged his real memories. Here's the problem with a clone army. What if they live? Totally survive the war. Millions of guys with the same boring face and the same identical genetics. 1. Women are going to get bored of tapping that. 2. Children. If 5 million Jango Clones are living on the same planet, and have maybe 3 to 8 million children on a plant that only has 20 million people are going to have to work hard not to breed inwardly, and their children are going to be surrounded by nothing but first cousins.
I don't think it was ever actually said, but I'm pretty sure the clones of Jango were sterile. My circumstantial "proof": 1. Look at how the three clonetroopers they came across on Star Wars Rebels were living - just the three of them together in their accelerated old age. No families other than each other. 2. They grow at an accelerated rate, including into old age. That isn't a trait you want breeding back into the general populace, even if you are a Sith, because that isn't EVIL bad, that's just bad bad. 3. The altered Jango genome was almost certainly proprietary to the Geonosians, so just like the way Monsanto keeps their GMO plants from producing viable seeds, I'm sure the Geonosians would have done the same.
Yes - I imagine Stormtroopers would act very childlike if left to their own devices - having been programmed for obedience & combat & nothing else. A lack of good social skills or critical thinking doesn't mean they are literally child-aged. There was an episode of Clone Wars where there is a deserter living as a farmer & he had half-breed children with one of those tentacle-headed ladies. At least I THINK they were his kids. Mixing aliens is a very Star Trek thing to do.
The Clone troopers were supposedly not sterile as it caused problems with them being aggressive enough or something. However a lot of them were probably sterilized in combat from various radiation sources on the battlefield.
They would be too old. The Clones Wars at that point would be maybe a year old and he'd have only deserted a year ago. As far as I know, we've not seen any mixed parent/species children in Star Wars. Though it is possible, since there are some near-human species in some background shots. Human and Twi'lek seem to be a common pairing. Though most Twi'lek females shown have been kind of hot by human standards.