Well amro is pretty unfair :p 

They really couldn't care less what age Cams is. If he did get upgraded to a rank A section that would mean he either has potential or he is dead wait. Not everyday someone survives as assault from a Vile. Also you can't survive the Jungle without clearing. You have to survive the Jungle to clear it. 

Also in Rank A basically any and everyone weak is weeded out. Consider it natural selection. If you don't have what it takes to survive it you will die. But those that do survive prove they are the alpha. 

Withdrawl symptoms vary. Hallucinations, extreme stress, paranoia, head aches, loss of rational decision making. Etc 

Time frame also varies. Some experience it after a month some after a week.  

Being an Unlinked has more disadvantages than perks. You will be shunned by most Asylums, you are considered a threat. Insanity will claim you quickly. But you have flexibility. You don't have a partner and you can join up Asylums to make a team of 3.