First of all, Rocky Balbudgie
I agree with Kellie, in that he may be going through a stroppy teenage period, but being reluctant to leave the cage and starting to develop cage territorial behaviour is a problem that needs intervention.
He wonít connect removal of toys with biting/lunging at you so there is no point in taking all his toys away. Maybe remove the swing if itís just that one specific toy that is causing the problem. If you want him to leave the cage, then outside needs to look appealing too; so if you havenít already, try to create an inviting area outside (top of the cage?) with perches, toys and food.
I would not put any treats in the cage. Take a few steps backwards and treat him like a new bird who has just been home for a few weeks.
Start by resting your hand on the cage for a while until he accepts that without objection.
Feed him treats through the bars and if he does venture out of the cage and you need to get him to step up, then get him to stand on a perch rather than your hand - These things will help you avoid instinctively jerking your hand away if he goes to bite - we donít want him to get confirmation that biting works at getting you to back off.
You can then progress to opening the door and holding a treat in the doorway.... then and the end of an outside perch... etc.