I use Trezor with Electrum. While Electrum won't import private keys, it will sweep them. Once you've done this your funds are under the protection of your Trezor. The only downside is that you will have to pay a small transaction fee to the miners. Importing private keys would be a bad idea, because you would gain no protection from the Trezor hardware wallet by doing this, which is why it's impossible. (And also why Electrum doesn't allow importing private keys.)
I view my real wallet as the piece of paper that I've locked up in a fireproof vault and that contains my seed words. If your Trezor is destroyed you can recover your funds from the seed words. You don't even need another Trezor as there are software wallets that can recover your funds. (But you will need to trust the computer you use.) $100 for a small, simple computer that you can trust sounds like a very good deal to me. Trezor wallets are very easy to use and I've tested them with Electrum and MultiBit HD and both of these programs can access my funds.