> Claw back his executive compensation
This is actually very problematic that a company can claw back compensation that wasn't previously agreed upon (with the exception of crimes).
Companies could have put this clause in the job offer. Yet they don't. Why? Because no respectable person would have signed such contract.
You wouldn't sign such contract either.
> fund better severance / transition support?
To continue the analogy of the cleaners, you don't provide severance nor transition support either.
In FB, the severance of 4-month minimum seems good.
> Forfeit bonuses for the fiscal year
100% agree! If the company's or their performance is bad, they absolutely don't get bonuses. This is coded in their performance/compensation review criteria.
If your employee makes 10 successful things and fails 1 thing, how much would you punish that person? probably none.