I have some old coins in multibit 0.5.10. While I have no intention of selling the coins anytime soon, I would like to have them in a wallet where if I decide to sell them I can have them on an exchange as soon as I fire up the wallet and hit send. It seems that putting the keys into electrum via this video:
https://www.youtube.com/watch?v=LaijbTcxsv8&feature=youtu.be is the way to go.
I have a couple questions about this. My Multibit key export has two private keys listed. If I enter them both into electrum at the same time is this okay?
Not only is it OK... it is recommended if you want to see ALL your MultiBit coins in Electrum
Second and most important question. If successfully import the coins into electrum and back up the private keys on electrum, will the coins be in the new private key backup? I have read things about coins not being in the backups of wallets they are transferred to. Here is an example of what I mean. I import my keys into electrum and my coins are now in electrum. If I export the private keys from electrum, will they still have the balance of my coins if I import them into a different wallet software? Do I get new private keys when my coins are in electrum?
If you "import"... you don't get new private keys
If you "sweep"... you DO get new private keys (sweeping sends the coins from old addresses to new addresses)
So, if you import your keys into Electrum and then Export/Import them into a different wallet, you'll see the same coins/transaction history.
However, if you sweep your keys into Electrum, they'll end up on different addresses/keys
NOTE: Electrum does not allow you to import private keys into a wallet backed up with a 12 word seed... you have to create an "old style" keystore... effectively just cloning the MultiBit setup. If you want to use an HD Electrum wallet, backed up with 12 word seed, you'd need to sweep your old multibit keys.
Third, if I just keep the coins in multibit on my old machine and keep it offline, would that be a suitable method of storage for years to come? Meaning, if I have the compressed keys from multibit exported and in 5 years decide to sell, will I still just be able to import them into another wallet and sell them?
Have a read through some of the threads here with people struggling with MultiBit after X years... they've discovered that "exported" key files are corrupted and cannot decrypt them etc... if your MultiBit is working now, and you can export your keys... I would HIGHLY recommend you do it now and either store your private keys in a different (more reliable) wallet like Electrum... or you write them down and keep them stored offline on paper... or put them in an encrypted text file (NOT encrypted by MultiBit!!?!)
Also, one last thing, electrum does let you export private keys, correct?
Yes