You're the first developer on board. Get more equity, 2% would be good if they are giving you half-salary. 1% would be good if they are willing to do full salary.
Walking away from lowball offers makes you worth more in the long run.
Walking away from lowball offers makes you worth more in the long run.
But I'm assuming you're a developer and the founders aren't and if they are trying to hire you, you have a certain set of skills they want.