Every time I get tasked somewhere, I read the OP/Admin Orders, do MY map recce of the AOR and find out if any air assets are available, and then I think about what I will need to bring. Then I pack my bag. Then I realize how heavy it is. (We tend to try and pack everything). So I lighten it. Regardless of how I pack, my bags are usually 35-45lbs, with water. I use a Camelback BFM with the Med Insert.
As you can see below, in the last 2.5 years I've had very different taskings. You will learn through experience, both yours and others.
as for the other part of the discussion. While in Afghanistan, I did air sentry all the time. Had no choice, due to manning. And honestly, I loved it. And yes our Bisons and then 113 Ambs were armed with C6's, the 113's had the RWS.
A portion of our mandate as medical pers is preventative medicine. If I can kill the rat for no good reason other than it MIGHT have fleas or MIGHT bring poisonous snakes around. Then why can't I start shooting at 200m?? <- Just for arguments sake.
Snapshot:
Ex Trillium Response 12: 90 + min North of Hearst, Ontario. In the middle of a Provincial Park. Totally dismounted. Assigned as the Coy Medic for 56 pers, with 6 plt medics and an LSVW AMB at the entrance to the park about 30-45min away. Evac to the Hospital in Hearst was more than 90 Min by land. No Helo extract available.
In Afghanistan 2010 : We pretty much had a chopper Not more then 30 min away and my bag was packed for trauma and hydration. I was all by myself either with the OMLT or RCD Recce usually not more then 8 to 14 pers. So I was mounted which allowed me to bring more in a 3rd line bag that stayed in the TLAV/LAV, as we were usually out for weeks at a time. Also did convoy duty for NSE Force Protection.
In Ft Irwin, California During Work Up 2010: I was again mounted with a Bison AMB as the GIB, got tasked out all over, usually on convoy duty or at the coy level. (ex was a gong show, if you were there you know). We had Airevac at about 20 min after the 9 liner.