Not sure about the TO in this case, but under normal waiver rules, it should be 75% for this season, and 50% for next season. So your contract drop should cost you 1.13M for this year and 1M for next.
I see where your thinking lies, since the next year is a team option (as opposed to being "buyout eligible"), that it may not count. But, to the best of my knowledge, it counts as part of the drop. My guess is you would have to be in THAT year of the contract to take the Team Option...otherwise, it counts as a regular year. I could be wrong on that or misinterpreting the rule though.
And the in-season max player roster is 16, not 15, but you're there with the drop, so no worries!