I think you already know the biggest mistake was not giving the deer some time. I know, I know I get giddy like a schoolgirl and want to rush right off too. The problem of course is when they run right off the land you have permission to hunt and track on.

The dark red blood could have indicated a liver or kidney hit. The hieght of blood sign on trees, weeds, could help you to know how high on the deer you got as well as the hair colors.

The blood sign going to light drips may not mean anything if the deer was running full on, the sign would be less concentrated then while standing or bedded where it can pool up. He could also be bleeding internally. If your arrow was covered all the way broadhead to nock, meaning a complete pass through, you should have seen blood on both sides of the trail and on weeds etc giving you further indication as to the hieght of the entry and exit wounds.