Installing onto x220t in UEFI mode

Question

I created USB following instructions here: https://wiki.archlinux.org/index.php/UEFI#In_Windows
Booting from USB will arrive to 4 options:
Arch Linux archiso x86_64 UEFI USB
UEFI Shell x86_64 v1
UEFI Shell x86_64 v2
EFI Default Loader
options 1 and 4 goes to some black screen with nothing appearing for some time.
option 3 goes to ASSERT_EFI_ERROR (Status = Device Error)
Option 2 goes to the UEFI Shell, but I don't know what to do from there.
Some info:
UEFI BIOS version 8det61ww (1.31)
UEFI BIOS Date 2012-04-25
Embedded Controller Version 8DHT30WW (1.20)
Machine Type Model 429636U

Answer 1

On top of the fact that UEFI is a bit to wrap your head around at first, you are also facing the issue of having an old UEFI version (1.31).  This is why the UEFI shell v2 doesn't work.  Though why the installer won't boot, I am not quite sure.  But it may be that you are running into the Intel KMS issue that is pretty common.  Try editing the kernel command line before booting and adding "nomodeset".  If it boots, then you know it is a graphics issue.
Even though UEFI might be hard at first, in my opinion, it becomes much much easier, and ultimately makes a lot more sense than the old bios/MBR way of doing things.  I think what made it particularly hard for me at first was the fact that a) like you, I ran into issues, and b) I already understood the basic process of how the old booting method worked (which just confused the hell out of me).
If you continue to have troubles with your system, hopefully srs5694 can swoop in and save the day (sometimes mentioning his name seems to summon him).  Otherwise, I am pretty sure that cfr has the same UEFI firmware version as you.  If your machine's firmware is the same as his, you might be in for a hard time in getting things working right.  I know there were a number of bugs he had to overcome to get his machine working with UEFI.