why the eff does anyone want justifications to do something forbidden before whats allowed. Like some one said Engagement does NOT mean that everything or partial things / or as you describe.. skinship 
that everything has come into action. Engagement is just a deal ..and a deal can go either way .. and no one actually begins / the transaction comes into action untill its LEGALLY declared. and thats Called Nikah.
however, If you thinkk that Islam is a joke and it has rules and regulations maybe not to break but to BEND ..which you are looking to do, bend rules then think again .about your faith.