Investing is risky I do agree with you there.
But also holding can be too.
I have had bitcoin lost from those very reason stated in the original post. Lost keys, passwords and entering the wrong bitcoin address for payments are all reasons that I have lost some bitcoin. Not that much but still enough not to forget about.
Holding isn't risky at all if you take the right precautions. If you do the following, then you won't have to deal with losing access to your coins.
- Making several backups of your wallet files and store each of them in a different place that can be an USB drive, external HDD, burn it on a CD or DVD, etc.
- Writing your passwords on a small piece of paper and hide in in a book or other place where you can find it but others not.
- Print out your private key and hide it in a book or other place where you can find it but others not. For extra security you can even choose to seal it in plastic. And this adds extra protection for when your wallet.dat files corrupt. You can always access your coins via your private key.
Preventing yourself from sending coins to a wrong address can only be done by yourself. Just double check everything before you send out the funds.