Theft is a material non-issue. The lack of a secondary market means the only purpose for theft is export / driving on the street of third world countries. Most of them don't want EVs.
What 240 plug do your parents have?
Yes, you can get a teslatap to use your Tesla mobile connector. Chances are you can also get an inexpensive ($20) adapter off Amazon to adapt the included rivian charger to whatever plug you have.
Sirius has some decent programming, but you can get it all via the cell phone app. The sat connection quality is just garbage anyways, I can't stand to listen to it.
As long as you don't need Live content (IE: Sports/News), you can cache days of music for radio stations for offline/backcountry...
They may just accept the 900 # payload, and likely reduced SAE tow rating, but increasing the GVWR down the entire line is often more engineering intensive that it seems, even if its only 200#. Sometimes it's a suspension tuning, rigidity of a part, or simply tire weight ratings push them to LT...
The one for my missing frunk port had a fuse. The one for missing dash did not. In any case, it's > 15 amp, and your duty cycle is low, so I think that radio will be fine.
Don't use obdii for a ham radio.
Fuse 28 I think... Left kick panel under driver. You'll have to make a fuse tap as the type rivian uses is exotic, but some trimming with pliers is all that's needed.
I used 15 amps because it's what's I had, but I think you could do 20.
220, but don't burry an extension cord unless you want a fire or electrician hazard.
Run conduit, and pull 220 on a plug in the distance. Plug in a portable charger. Do 14-50 if budget allows, otherwise do whatever makes sense.
One more nuance is depending on the state, all those medical bills may be subrogated before you see a penny. Law recently changed here for that to be more split, but it's not that way in a lot of places.... Enough to make one not care to pursue.
Almost all punitive damages are dismissible unless it's due to gross negligence. Gross is a high bar, thing if things like drunk, drag racing, near kids in a school zone type bad.
Mere negligence, like texting and sideswiping, will go away in BK.
Keep in mind the legal costs to get there...
It's really not rocket science for a simple install, as simple as they get. Pull a homeowners permit (+$200) if you're worried about it. Building the experimental aircraft was far far more complicated. Wiring the shop far more complicated.