What insecurity you actually talk when you talk about hardware wallets? Show me one example that anyone is lost any coin as a result of hacking hardware wallet? Caution is in the world of cryptocurrency most important thing, but the way you're thinking is actually paranoia...
First of all, as I understand it the ledger nano wallets show your seed on the screen so at that point, that seed should be considered compromised as it has touched the internet.
Secondly, I'm not sure how many people compile the binaries fro themselves instead of running the exectuable so they cannot determine it's safety.
Thirdly, they used to use a google chrome extension, if tere's a browser that is the worst for being infected with malware and worms it's chrome...
Ledger support Banano because it is just fork of Nano and it was easy to add it, it is not fork of ethereum network as you say - you shoud do more research before write such things. I agree that most of forked coins do not make any sense, and this is also case for Banano - but since many Nano holders get Banano I do not see why Ledger would not support this coin, there are many coins ever worse then this one.
Oh I take it back then...
Ba-nano - I get it now

... Cool name.