This means that the initial launch is approximately 400000 (3333 * 5 * 24) DAY tokens.
Nice foresight, you weren't very far off!
As for the different scenarios you have described, I won't speculate on what will happen but certainly people with the first TimeMints will have an incentive to buy up more tokens since they have the ability to mint at a higher rate than anyone else.
But not all DAYS will remain on TimeMint addresses over all the time.
You are right, a number of tokens will likely end up being traded and thus on other peoples wallets or exchanges which don't mint new tokens as TimeMints do.