Running Kali Linux on Virtualbox in a Ubuntu Bootable USB

Hello,

1 - Is it possible to create a Ubuntu Bootable USB stick (as instructed here: https://www.ubuntu.com/download/desk...ick-on-windows), install VirtualBox in it and then install Kali Linux on a virtual machine there?

2 - If it's possible, how should Kali Linux be installed? Downloading the latest release ISO and installing on a VM as one would normally do? Or downloading the custom Kali Linux VirtualBox Image? Does it make a difference?

3 - Apart from the virtualization probably increasing lag and low performance, does it break any functionality in Kali?

4 - Is it safe to assume that such USB stick can be used on different computers/hardware configurations without breaking any of the installations (both Ubuntu and Kali)?

Kind regards

First what you want to accomplish?
To get Kali on USB ?
Then just install Kali on USB (read here on forum how to make it) and do not complicate with Kali in VB on Ubuntu and everything on USB