Two Computers; One Account - How do I avoid locking myself out?

[Lexia]

I distrust that I wont lose phone/it will die somehow so I wont use the phone app,

That why they give you a removal code, so the security token can be removed from account if this was to happen.

[Niqote]

That why they give you a removal code, so the security token can be removed from account if this was to happen.

It's far easier for me to use my same trusty old 1.0 security token XD.
I have another one as a backup already from the ARR box for the day it eventually perishes... if that day ever comes. /herosneverdie

[KisaiTenshi]

Use the security token app. It's a good idea in any case.

This. I've never had a problem using it.

That said, make sure you follow instructions for removing it when you do major OS updates or you will have the same problem.