@huanghq
thanks a lot for creating this walk-through it was so useful
I do not think that USB stick is safe wallet - there can be a lot of problems. For example, there are viruses, that use USB stick. And if you use one Linux OS - you can use only that one Linux OS, so you can not use USB stick in other machines with different OS then.
i have never head of virus on linux! there is none.
the only risks for using this way are: forgetting your passwords and damaging USB stick physically nothing else comes to my mind
and for preventing these two you can write your seed and/or passwords on a piece of paper and keep it safe
The viruses can be wrote on USB device firmware.
So don't use any untrusted USB devices (include keyboard,mouse, charger) on wallet PC or mobile.
and don't plug the USB stick into untrusted PC.
Don't flaunt your funds.