saying that actually he won't be able to go out at all! unless he's done the basics
For many teens, that authoritarian approach just leads to more deceit and secrecy - sneaking out in the night, climbing out if windows. Not a great way to develop respect snd trust in the teen-parent relationship. That said, it may well work for other children.
this behaviour simply not acceptable and we won't tolerate it in or you will have to consider leaving if it carries on. I may have to look at you getting a job, finding your own flat.
He's 16. Throwing a child out of home at 16 means Mum amd Dad both deciding to renounce your parental responsibility to social services and child going into a care home. Far from that solving anything, it will make his life chances far, far, far worse.
Even at 18, "finding a flat" is near on impossible. Have you looked at the rental market? Landlords can pick and choose, and they won't chose an 18yo kicked out of home. You'd have to guarantor for him and pass affordability tests to pay his rent as well as yours. You'd have to get him massive amounts of deposit cash upfront. Even children that want to leave home at 18 and are supported find it hard to find somewhere. He'd likely end up in a dingy house share.
That would all likely make the risk taking escalate. I don't think it's actually solve anything. Reminds me if the saying to take a sledge hammer to crack a nut. Just treat him like someone you love, care about, want to understand snd are willing to negotiate with - from that will grow respect, trust and responsibility.