how so?

They sent you an email, when they stopped trading Namecoin. It gave you a specific amount of time to remove them from the exchange. It explained the monthly charges for them to continue  holding them for you. The monthly charges were excessive to encourage you to remove the coins. You didn't remove the coins and the monthly charges resulted in you losing all your coins.

It wasn't theft.

Becareful when you post there's no need to post the same thing just merge them to avoid double posting.Yes electrum is safe afaik and i'm also using their wallet. Always save/make a backup so you won't lose access of your coins.

transfer em over to another wallet that you can control your private keys.

Try out:
Windows: Electrum
Android: Copay / Mycelium
iOS: BreadWallet

option 1:
choose one of the hardware wallets that are currently available, such as Trezor or Ledger. buy one, learn how to use it and transfer your funds to that. fast and safe.

option 2:
learn how to use bitaddress to generate a paper wallet. do that, print it and send your funds there.

p.s. if by cryptocurrencies you mean multiple altcoins not bitcoin, then i believe Trezor or possibly others support some other altcoins such as LTC too. also there is another project (which i don't know if it is good or not) which is similar to bitaddress and generates paper wallets for altcoins
here is the link: https://walletgenerator.net/ but i don't know if it is trusted like bitadress or not.

You installed it wrong.  "read-only" IS an option during the install.  do it again;)