Yeah I'd say that myethwallet is pretty safe. If something is open source client side then you should still always run it without internet just to be sure. Hwever the code whether it has been audited or not I am not sure. But still, if you are storing only small amounts I think it is alright to trust myethwallet.
I have stored all my XAUR there which is amounting to 2k. Its not so much as its price hasn't changed much as of now. I'm not installing any wallet because i only have few gig left to my drive. Currently. I'm buying some tokens, I will also store in myethwallet.
