Is anyone using the Coin98 wallet? Could you share some reviews?
I see it supports multiple types of coins, so I'm considering switching to this wallet.
you should get a hardware wallet (not ledger) for your bitcoin and eth, as for the other coins, don't take the easy route, follow the advice others mentioned, and you should be safe.
and always remember, never trust, always verify.
And can I generate keys securely first and then use a closed-source wallet?
why would you do that? it's essentially the same as using a closed-source wallet from the start (just with extra steps), if not worse in terms of security.