In the OP you mentioned a beta of the ad system in 3 weeks. Are you planning to do this work yourself or outsource it? The pre-mine would likely not go very far for the Dev work needed.
Most importantly......do you have the resources to see this through as it sounds like it will require a great deal of time. It would be much more challenging if you are working on it on the side or when time permits. If you cannot follow through with the plan in the OP for whatever reason letting it go to someone else may be best.
I agree with above, a clear direction is very important for many. (not all that may only be in it for 21 days or less)
Bittrex is gonna massive stake this coin, I wonder where those coins go? Could they be released to OCminer for premine, and used for promotions?
Vegas
Its probably not going to work, but they need to get this coin either going by trying to get it to stake with this redulously high diff. If that happens staking will not be an issue, once that happens they can maybe get it to start pow again, and then at a future time not to far, end the pow properly and start the proof of stake right.