@raynbow- I have used finishing spray on my face, and it is definitely not something that I would want to include in my beauty routine every day. To me, it felt very strange once it dried, almost like I was wearing a mask.
The good thing about a face finishing spray is that it does keep your makeup in place, even when the weather is hot and humid. Since you have events that you want to stay looking fresh for even if the weather is hot, I think that you will be happy with the results you get from using a finishing spray. Just make sure that when apply it, you give it enough time to dry before you go outside. If you don't, it will run and smear right along with your makeup.