Reddit reviews Stansport Deluxe Freighter Aluminum Pack Frame, One Size

Strap to a frame like

https://www.amazon.com/Stansport-Deluxe-Freighter-Aluminum-Frame/dp/B001RL5PHY/

Yes! What you do is get a frame back pack with just the frame, put the gravel in a burlap sack, and strap the sack to the pack using either bungee cords or paracord. Something like this is ideal https://www.amazon.com/Stansport-Deluxe-Freighter-Aluminum-Frame/dp/B001RL5PHY

I got some straps like these at the hardware store and fastened my case to a pack frame like this one. It's decently comfortable.

Theoretically, yes.

Get a few of the batteries, each of those is only slightly larger than the built in battery, you will be lucky if you get about a half hour each.

Also, for the pack, go with a frame.

https://www.amazon.ca/Stansport-Deluxe-Freighter-Aluminum-Frame/dp/B001RL5PHY/ref=sr_1_1?ie=UTF8&qid=1458344933&sr=8-1&keywords=hiking+frame+pack

Carrying that much on your back is always going to look stupid, so at least make it comfortable.