That said, I still don't get what you said above - will need to read it three or four more times
I find it sorta tough too and have to revert back to google A LOT. it wont stick to my brain.
In short: All electric heaters are basically the same despite the marketing.
Everything else, ask @ernesto
Also we live in ring circuit territory because of ww2 copper shortages so doing most sketchy shit is sorta safe, or at least protected.