First dump your keys using the instructions here
Then open a new Electrum wallet, ask it to "Import private keys", and paste your private keys there.
Then you will be able to spend from there if you have coins.
You can use it. Electrum, nowadays, is as popular as Multibit used to be, so you can assume that you will always be able to recover your coins.
To be safer, you can export the private keys from Electrum and save them in an encrypted archive such as ZIP or 7zip. (But you need to do this every time you make a transaction)
What I would actually do would be to ...