It seems to me that there is in fact no need to gather food for the crew in the first round (if more than 6 were needed), since I recall a rule that states that one cannot have negative points. So, in the feeding phase, no points are lost, and then points for building are only acquired later.
Am I right?
(Obviously, it is not very humane to let the crew starve, but there you are...)
Not sure where you got that. Page 4 of the rules clearly state:
If the player has less grain, then he must lose points on the scoring track.
His score may go below zero.