My current pay is probably 10-15% above average. Funding is more to the 2-4 range. My main concern is whether the equity is within the "average" for first developer on deck in a startup with VC money
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.