For your second question, no, there are some wallet you can import the privkey to, but HD wallets work differently. If you had setup Multibit HD first, it would have taken few minutes to fully sync, probably.
which wallets would I be able to import my key to? and will the btc show up as soon as it's done syncing automatically?
thank you for the informative response!
Electrum, multibit does not use the same backup format, hence you can't import using wallet.dat. CMIIW, I never import wallet.dat into electrum or multibit directly successfully. You have to go to help>debug window>console. If you have a password, enter this:
walletpassphrase [password here] 600
then to extract it, use
dumpprivkey [address here]
. But Shorena has advised me to avoid touching the private key unless nessasary. I would keep a backup of the wallet.dat first before doing anything.
For Electrum, you can choose to import or sweep. Importing means that your address will be included in the wallet the seed cannot restore it. Hence, you need to keep a seperate backup. Change are also sent back to the origin address. Sweep means that your balance would be sent into one of the address generated from seed.
Multibit no longer supports the importing of private keys. I suggest that you use Electrum.
Multibit Classic? I have always used it. Just need to add the private key in the .key file.