RE: flash scare deer???
I've never seen any evidence that deer or bucks for that matter have any lasting fear of my cameras or the flash. If they are wound tight I've seen them jump and run and I've seen the same buck just stand there and get multiple flash pictures taken. I have even had multiple flash pictures of bucks laying down over long periods.
My one caveat is that I believe that there may be some deer whose personalities do not like the flash or anything foreign in their territory. I do not know this for a fact, but through all of the pictures I have it sure seems that some deer have different personalities. I also believe that older bucks often get more reclusive and I'm not sure if this means that they become afraid of cameras or if they just move less and stay away from any human contact.
I don't know if we'll ever completely figure them out, but they sure are fun to watch.