Since a number of your schools do not have finance at all, and you got an 800 math, I do not think math will be your problem. I think you will be perceived as a good student that hit a few bumps in the road. I have a slight concern with your recommendations and the fact that you requested 4 - and some seem better than others. No need to explain, but something feels a bit off there to me.
As far as your real question goes; how to make yourself a stronger applicant, I would look for commonalities among your activities and think hard how you are going to present them to colleges - using the format they offer. I like what you did with debate, and maybe you should have similar depth with your venture and then choose a few other things that can make you really deep in maybe 4 or 5 things - and then the rest can be filler. That will be understandable because of how far you have gone in your best few.
Hard for me to imagine ivy’s/Stanford are possible, but I will not count you out from the others listed assuming your school is one of the true top. Good luck.