Let's talk about the worst case that might happen, what will you do to the unsold coins when nobody is buying your coin?
And what will you do to develop the project if you do not collect the fund when the sale happens? will you abandon the project or what?
Also, will you do the staking when the main net begins? if you are running it then what will you do to those staking rewards? Will you keep it or sell it?
0% dev premine sounds silly to me, it is ambiguous.