When will the new coin's forum thread be made? On the 25th?
I believe the new thread will be created once the distribution has been completed and verified by this community.
Any idea how many of the new project's tokens we'll be able to purchase per BITS
That isn't something which can be known beforehand given the distribution method. Not until the submission process has closed and all BITS deposits are in can the proportional allocation be calculated.
and how many total will be available?
No information about the coin is being given out at this time in case any last-minute adjustments are needed following the final testing which is taking place.