Thanks for the help and replies. The reason I'm asking so much about this is that I did import the Mycelium seed into Electron Cash (after first emptying my Mycelium wallet of btc of course). But the balance that shows in Electron cash is less. All the inputs are correct but the outputs don't all coincide with what are in the Mycelium addresses. That's why I wanted to import the Mycelium key/ keys, as opposed to just the seed, into Electron Cash doing Sweep.
Another problem with Electron Cash is that all the entries in the transactions says "not verified"