They are not, no import statements work in javascript right now. You’ll have to remove all of the import statements in all of the “Begin experiment” code components.
It depends what you’re trying to do with them, mostly. For shuffle, you have to create your own shuffle function. You can find a simple one that you can copy into a code component here: Reference error: shuffle is not defined
For any other sort of randomness, you can just use Math.random, which is built in to javascript.
For time, I’m not sure what you’re trying to do with it, but there are various util.Clock functions that should work.