>> Examine the device next to the panel-door of the east wall.
>> put keycard in the circle thingy slot like the american gas station card readers... And do it the Irish way!

You have no idea what the IRISH have to do with KEYCARDS and CIRCLES, but you examine the PANEL anyway.

The PANEL itself consists of an outer square with a circle inside of it. It's hard to tell, but the part inside the circle seems different somehow, like it's not as rock solid, or depressed into the WALL, or something along those lines. Jutting outward from the center of the circle are two lines made of stone in some strange, nearly T-shape formation. None of this makes any sense to you, but it's clear your APEX RED KEYCARD won't be of any use.

>> Examine green and orange buttons on the bottom row for hints.

Actually, it looks as if the GREEN and ORANGE BUTTONS are probably CONFIRM and CANCEL BUTTONS, respectively. There's nothing on them to indicate the KEYPAD's desired CODE.

>> Check Red Key Card for any 4 digit number that may be relevant to our door opening needs

Nope. It just says APEX on both sides, remember?

>> commence OPERATION PASSCODE CRACK!!! By process of elimination, put in 4 digit codes into the pad until you get the right one. Make sure to start with the classics (0000, 1111, 1234, 5678, 8008, 1337, etc), then move on to basic probability and mathematics.
>> Enter 4 0 9 6 into the KEYPAD.
>> Enter "13" onto the Keypad.

You input a wide array of PASSCODES into the KEYPAD and hit the CONFIRM button each time, but every time, it gives a faint buzzing sound and resets itself. None of your GUESSED CODES seem to be correct...

>> Sing along while entering 8675309.

"Eight. Six. Seven. Five. Three-oh-niiiiiieeiiine."

The KEYPAD rejects your number, but it was fun all the same. You even gained 15% TOCCATA EXPERIENCE for your MUSICAL INTERLUDE!

...Oh, wait. That was...seven numbers. All of your ATTEMPTED PASSCODES so far have been 4 numbers (or 2 or 5, that one time.) You fiddle around some more, and it seems the KEYPAD can accept up to seven numbers...but that doesn't mean the correct CODE needs all seven. The amount of possibilities this CODE could be just went from "a whole lot" to "near-endless".

>> Throw yourself face-first into the keypad until the door opens.

MMOEPAWFGEPH. ...No effect.

>> If that doesn't work, then ask the MAGIC 8 BALL for some advice.

Okay, the amount of possibilities just went down to "near-endless-divided-by-three".