Is it possible to set up a multisig electrum wallet and also do regular transactions, on the same wallet? Or would I have to have a second electrum running on a virtual machine or something like that? I wish electrum would enable multiple accounts on the same HD wallet, like mycelium does. That would be very useful.
You need different wallet files, but there is no need for a VM. You can open several electrum wallets at the same time.