RE: Straight down shot
Last year, I had 3 bucks come right to me and the lead buck was a 9 point bruiser. I was shaking worse than a leaf on a tree. Sure enough, he first ended up underneath some limbs preventing me from taking a shot. Then he proceeded to walk right underneath my stand. He was jumped from other hunters I suspect as he was very jumpy.
I couldn't take that shot either but he slowly moved from under my stand and revealed a between the shoulders shot. I drew back and remember thinking "how much do I have to arc down just to make this shot happen?"
Finding my peep in that capacity was very difficult. Anyway, I thought I found it, lined up the shot, and took it. I have practiced this shot but not quite like this. I missed his whole body by a couple inches. Of course in hindsight, I thought I should have waited for him to move further out. Thank God I missed him. Injuring any deer especially one of his stature would have really sucked.
So the answer is to always wait for a shot you know you can take. I know sometimes it's very tough thinking you might only be provided what is given to you since they could bolt at any second. Not worth it, wait it out.