ad 3. You are buying overpriced Bitcoin, because they are "special". Oh, yes, that is really sane
You don't need to buy a whole bitcoin, few satoshi is enough. You won't notice this purchase even if you pay 1000-fold.
ad 4. What if, there are just small unknown exchanged, that work with the weaker chain? How long does it take to register there?
Ever heard of off-exchanges trades?
ad 5. Selling your Bitcoin is always risky, especial if you exchange them for another cryptocurrency.
Selling your Bitcoin is always risky? Not for fiat, last year clearly showed that those who sold did a smart move. I hope you won't try to argue that keeping bitcoins during a panic is a smart move.
"There is no free lunch", if someone tells you otherwise, he has no idea, what he is talking about or is trying to scam you.
Agree on that.