I like a border on the edge.. but you could make it very simple since you don't have a lot of time.. Perhaps just a plain border with a pieced block on the 4 corners?/
I love the triangles, that's a great look, but I think they need to be bigger. Maybe 1/2 the size of your orginal center block? If you have time and fabric that would look wonderful! if you don't have time, don't worry about it. It's a great guy quilt and he is going to love it.