RE: Fixed or mechanical broadheads
I'm kinda going through the same thought process. Really like the way the mechanicals fly, but a lot of my fellow archers out here think they are risky - particularly on elk. I have also heard credible stories about angling shots where the expandable caused the arrow to deflect and stay on the outside of the ribs. This was on an antelope, which is not a very heavy boned critter.
There is also quite a bit of discussion about whether one needs a heavier bow to get good performance from mechanicals. Takes a certain amount of energy to get them to open.
Expandables also seem "safer" in terms of the potential to accidently cut yourself.
One head that seems to be shooting pretty well for me is the G5 Montec. They have a great reputation for elk. I'm sure they would shoot through a deer even with a low poundage bow. Just takes a little more tuning to ge them to impact the same spot, and the ability to sharpen them.