I think criticizing them is valid and even though you have significant bumping power your post provides the thread with only the minimum bumping power the you can generate. Also, I don't see anything wrong with bumping a thread that you feel needs to be criticized, it'll give exposure to the fact that you feel it's a shady project. Just my opinion.
I don't know if that's really a good thing. The thread is going to be on the front page of the board for a day or so, and presumably get a slight boost in Google rankings, with my comment buried somewhere on page 400.
The other thing that I can't quite get my head around is how the weekly post window works. If I post on the thread every day then according to the formula in the OP:
If you haven't posted in a topic in the last 7 days, posting in it adds 1% of your base bump power to the topic's bump score. Deleted posts count against the 7-day limit, but not the topic's bump score.
it would seem that only the first post will bump it, since every subsequent post that is still in the 36-hour window will have up to 6 previous posts in the 7-day window... so no bump?