Nice and well thought out piece of writing.
Some of the mistakes you mentioned are not limited to bitcoin newbies but even pro make these mistakes like Trading any random Altcoin or buying at sudden price rise.
Anyway I appreciate your efforts in putting this up and hope nobody make these mistakes

Altcoins themselves are a mistake.
But the first one is no longer a mistake it's more like a trend.
I doubt there are more than 10% on this forum that hold their coins in their own wallets.
I read a thread where for two pages everybody was using blockchian,coinbase xapo and so on