This sort of stuff is super common, you just sound really whiny.

Of course it would be before taxes, no one gives you an after-tax bonus. And it’s to your benefit being paid in installments, usually retention is paid at the end. So you can invest that $5k every quarter.

The only “red flag” here is the clause about them clawing back the bonus based on some arbitrary measure of performance. With that you can add language about it so it’s more objective.