Hot rod heater in the bed install help

I have a 2017 Tacoma sport ext. cab. I'm looking for help installing a hot rod heater (Jegs 260CFM model) into the bed to heat the space inside my camper shell. Instructions say it should be as simple as connecting to the coolant lines and adding a 15amp MR fuse but, Im hoping for help understanding..
1. If this is a good idea?
2. Any one done this before?
3. Any ideas on how I would go about this?
4. What type of flexible pipe would be best?
5. How to install a 15 amp manual reset fuse?
6. If there's a best route to run the pipe into the bed?

 

Get a small vented portable propane heater that's rated for RV's instead, better than running your engine all night. Also, I think you will have to put a lot of insulation on your hot water coolant hose to keep it warm enough for that hot water dependent heater to work well.

https://www.google.com/amp/www.doityourselfrv.com/easy-catalytic-rv-heater-mod/amp/

Be careful with that exhaust hose though, keep it away from any open cab windows (which you should have at least one open to let fresh air in), and also get a battery powered carbon monoxide detector just in case.

 

Those heaters are a common feature on school busses up North . Some passenger Vans also use the heater

 

Ive got one in the back of my carpet cleaning box truck to keep things from freezing in the winter while driving. Just use regular coolant hose, its quite simple and maintanence free.

 

I'm only looking to heat the shell while I'm driving. (Dogs, paint, liquids, etc..)
So propane's probably not for me.
I'm mostly interested in generation three specific technical details that a novice mechanic like myself might be unaware of.
I've read about guys that have done this on other trucks, I know it's possible..