Some cherrys are poisonous and some are not. Not sure about the redbud as I beleive there are several different kinds of redbuds. I would find out the latin name of the trees that you want to put in and then go from there.
There is a listing of poisonous plants in the Central NY koi website.
http://www.cnykoi.com/articles...
I will say, that whatever goes into your pond will have to be taken out, as the leaves, fruit, whatever - will rot in the bottom of your pond if you do not remove it. With rotting leaves, twigs, fruits will come disease for the fish.
Also, I have a Kwanzen cherry tree by my pond. I keep telling my husband I am going to have it taken down, because when the leaves and the petals fall, it is about a week or so of intensive pond skimming and cleaning out my skimmer and that is without fruit. I probably won't take down that tree - but I need to really stay on top of things during those time periods or I will have a problem.
