This one is likely enforceable.

There is a difference between individual clauses being invalidated and the whole contract being invalidated.

The you will surely agree to be permanently barred from looking at, commenting, writing or otherwise contributing to code if you write a bug I deem severe enough?

Seems reasonable to bar someone from contributing code to a project who _knowingly_ contributes severely buggy code

I wasn't aware you needed a license to code.

With the way peasa- I mean citizens talk these days, they'd say breathing should require a license.

Is this like a feudalism joke? I don't get it.