Hi,
An education of more than 18 months or 3 semi-annual semesters, which is interrupted and later resumed and completed, meets the conditions for giving right to unemployment benefits after the graduate rule.
Off course provided that you meet the other requirements for being eligbile as graduate. And you are right one of them is that you must have stayed in Denmark right before starting the education and again at latest 14 days after graduation. The fact that you have stayed outside Denmark during the education is not a problem.
It is the arrival date in 2012 which is important/relevant regarding your right to unemployment benefits.
What kind of proof the A-kasse will ask you, I can not say for sure. Normally a tenant-agreement will be a good proof. When CPR was registered is not relevant in this regard.
best regards,
Anders Weber, A-kasser.dk