So newb question here, I have the trezor and the ledger and myetherwallet.com
Im a bit confused about what is needed to get into your wallet?
1. Is the "back up wallet" a sensitive file?
Yes. It contains the information necessary to get your private keys (and probably the private keys themselves). If someone were to get access to it, they could take your coins.
can i just back it up on my dropbox and a few other places so I dont lose it, or does it have to be somewhere offline?
It is recommended that it remains offline, but if you think your password is strong enough and the wallet encryption is strong enough, you can keep it online. I wouldn't recommend it though.
2. Do you have to write down your private keys? will you ever need it?
You shouldn't need to ever backup individual private keys.
Can someone get into your wallet with the private keys?
Yes. Anyone who can access your private keys will be able to spend your coins.
3. Can someone re create your wallet with the master 24 words password alone?
Yes. All of your private keys will be derived from those words, so anyone who gets it will be able to get all of your private keys and spend your coins.
